REM-Fit 400 Hybrid mattress review: the comfiest mattress I’ve ever slept on
LOOKING to upgrade your knackered old mattress? Trust me, your body will thank you for investing in something premium - and the REM-Fit 400 Hybrid could be just what you need for that perfect night's kip.
This dreamy mattress combines 2000 independent pocket springs (which means your partner won't feel you tossing and turning all night) with layers of super-comfy memory foam that provides serious comfort and banishes those morning aches and pains.
Don't stress if you've got a bigger bed frame - the REM-Fit 400 comes in every size imaginable, from small UK singles right up to Super King, so you're sorted whatever your sleeping setup.
After months of rigorous testing, I can honestly say this is the comfiest mattress I've ever slept on - and it could revolutionise your sleep too.
Want to explore more options before making your decision? Check out our round-up of the best mattresses on the market right now - we've tested everything from memory foam to hybrid options to help you find your perfect match.
And remember, a great mattress deserves equally brilliant pillows.
Have a look at our complete guide to the best pillows that'll complement your new mattress and take your sleep quality to the next level.
Tested: Autumn 2022
REM-Fit 400 Hybrid Mattress, from £769
Quickfire Q&A
How much is the REM-Fit 400 Hybrid mattress?
THE REM-Fit 400 Hybrid mattress represents serious value for money, especially when compared to other premium mattresses on the market.
Currently, a king-size REM-Fit 400 has a retail price of £1,039, positioning it as a mid-range option in the premium mattress category.
The complete price breakdown across all sizes shows:
- UK single: £769
- UK double: £999
- UK king-size: £1,039
- UK super-king: £1,149
Remember that while this represents the standard pricing, REM-Fit does occasionally run promotions throughout the year, so it's worth keeping an eye on their website if you're planning a purchase.
Who's it best for?
The REM-Fit 400 Hybrid shines for side and back sleepers craving that perfect balance of sink-in comfort with proper spine support.
I was genuinely impressed when it came to my back problems, and I saw significant pain reduction after switching mattresses.
Couples will love how this mattress minimizes partner disturbance, while hot sleepers will appreciate that despite its cosy memory foam layers, it doesn't trap heat like many competitors.
What we loved:
- Provides excellent back support
- Incredibly comfortable
- Good to share
What we didn't love:
- Nothing notable
Rating: 5/5
How I tested
Rather than settling for superficial impressions, I slept on the REM-Fit 400 Hybrid mattress every single night, experiencing it through different sleeping positions, temperature changes, and sharing scenarios.
My testing focused on key performance factors: comfort level, back support, edge stability, motion isolation, and temperature regulation.
I tracked sleep quality using both subjective feelings upon waking and objective measurements like morning pain levels and nighttime disturbances.
I also tested partner disturbance by having someone move around on the other side while I attempted to sleep.
REM-Fit 400 Hybrid Mattress, from £769
Unboxing and First Impressions
At this point, I’ve tested out A LOT of mattresses at Sun Shopping, and I will say that the REM-Fit 400 won’t win any prizes for presentation.
It came rolled up in some plain plastic wrapping that was functional, if not attractive. However, that’s not exactly a deal breaker since I quickly got to work unwrapping the mattress and getting it on my bed.
Plus, the reason for the minimalist packaging is down to REM-Fit's goal of reducing unnecessary packaging, so I can't argue with that.
Like all mattresses-in-a-box, the REM-Fit 400 will take a few hours to expand fully after you release it from its shrinkwrap and, like every other mattress of this type, it smells a bit plastic-ey on opening, which may hang around your room for a couple of days.
After a couple of months of testing, I can confirm that the mattress expanded without a hitch, and the smell was gone in short order.
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Performance
I loved the REM-Fit 400 from the off and am happy to report it was the comfiest mattress I've ever slept on.
Not only is it incredibly cosy (something that will come into its own in the winter months) it’s also very supportive.
I have suffered from sporadic back issues over the years, and I found the 400 mattress helped alleviate this with its supportiveness.
If you’re a hot sleeper, you might want to consider a slightly firmer mattress, such as the REM-Fit 500 Ortho Hybrid mattress, but I haven’t struggled with the heat on the 400 I tested.
As it’s a softer mattress, I'll say you can feel each other moving around the bed a bit, but not in an uncomfortable way, and not enough to wake you up if you’re already asleep.
Again, if you’d prefer something a bit more rigid, the REM-Fit 500 option is available as well.
I found in testing that you can fit regular sheets over the 400 mattress, but they’re a bit stretched, so if you’re converting from a thin mattress, you may want to consider investing in a couple of sets of deep bed sheets to make your life easier.
REM-Fit 400 Hybrid mattress review: The verdict
This REM-Fit 400 Hybrid mattress gets five stars from me.
It ticks all the boxes: comfortable, back-supporting and cosy.
As I've said, if you prefer a firmer mattress, there are other options out there, including the REM-Fit 500 Ortho mattress.
But, I was thrilled with this mattress and couldn’t find any faults to pick.
REM-Fit 400 Hybrid Mattress, from £769
How long does it take for a REM-Fit mattress to expand?
Good news for impatient sleepers! Unlike some mattresses-in-a-box that can take forever to reach their full size, the REM-Fit 400 Hybrid mattress expands impressively quickly once you've wrestled it out of its plastic wrapping.
Most REM-Fit customers report their mattress reaching its full 25cm height within just 2-3 HOURS after unboxing.
One reviewer even mentioned it happened "so quickly I missed taking a picture" – that's proper speedy!
As with all vacuum-packed mattresses, you'll notice a slight chemical smell when first unwrapping (completely normal), but this typically disappears within 48 hours with decent room ventilation
.For best results, we'd recommend:
- Unboxing your REM-Fit mattress directly on your bed frame
- Removing ALL the plastic packaging completely
- Giving it at least 3-4 hours to fully expand before sleeping on it
- Opening a window to help any initial odours dissipate faster
The brand actually recommends a 30-night "bed-in" period before making any decisions about the mattress.
This gives both your body time to adjust to the new sleep surface AND ensures the mattress has completely settled into its permanent shape.
But make no mistake – while it might take your body a month to fully adapt, the actual mattress will be ready for sleeping within hours of unpacking.
Perfect if you're desperate to dive into that cloud-like comfort ASAP!
How deep is the REM-Fit mattress?
The REM-Fit 400 Hybrid mattress boasts an impressive 25cm depth, packing multiple layers of premium comfort into its substantial profile.
This thickness contributes significantly to that luxury hotel-quality feel that makes this mattress stand out.
Unlike the slimmer REM-Fit Pocket 1000 (which measures just 20cm), the 400 Hybrid's extra depth comes from its sophisticated construction - combining 2000 premium pocket springs with multiple foam layers for superior support.
This substantial depth remains consistent across ALL sizes - whether you choose a UK single or splash out on a Super King, you'll get the same luxurious 25cm profile throughout the range.
During testing, I found standard sheets felt somewhat stretched over this mattress. If you're upgrading from a thinner model, investing in deep-pocket sheets will make your life considerably easier and ensure a perfect fit.
Where are REM-Fit mattresses made?
Proudly British-made, REM-Fit mattresses are manufactured right here in the UK.
This local production gives the brand complete control over every aspect of quality - from selecting premium materials to perfecting the final construction.
The UK manufacturing base isn't just good news for quality control; it also supports their impressive 15-year warranty commitment - one of the longest guarantees you'll find in the mattress industry.
For those concerned about environmental impact, there's another bonus to REM-Fit's British production - a significantly reduced carbon footprint compared to mattresses shipped from overseas factories.
Is a hybrid mattress better than a memory foam mattress?
The hybrid vs memory foam debate isn't as straightforward as crowning one definitive winner - it's about finding what works best for YOUR specific sleep needs.
Hybrid mattresses like the REM-Fit 400 combine the best of both worlds - supportive pocket springs underneath pressure-relieving memory foam layers.
This construction delivers several key advantages over pure memory foam models: Superior temperature regulation is perhaps the biggest benefit.
Those 2000 pocket springs in the REM-Fit 400 create natural airflow channels that pure foam mattresses simply can't match - perfect if you're someone who sleeps hot and wakes up sweating.
Enhanced edge support is another hybrid advantage, with those robust springs preventing that annoying "roll-off" feeling when you sit on the side of your bed.
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For combination sleepers who change positions throughout the night, hybrids typically offer better responsiveness, making movement easier compared to the deep "sink" of memory foam.
That said, if you're after maximum pressure relief or share a bed with a restless partner, memory foam's superior motion isolation might make it your ideal choice.