So after skim reading through the thread and browsing websites for a couple of days now I'm still struggling.
Option #1 would be the premier inn mattress as both my partner and I always stay at premier inn's when we travel, if possible, as they are always comfortable. unfortunately the reviews for the company that supply the mattress are horrific and are at 31% 1 star ratings so I think they are ruled out.
Based on many of the opinions here I'm leaning towards JR but I'm moving in 2 weeks and ideally will have a new bed from day 1, they do have the mattress I am looking at as clearance but still not sure how much I like the idea of a returned mattress especially for such a small saving and there is a good chance its a straight no from my partner. (I appreciate a hotel bed is slept on by 1000's of people in its lifespan but there is something different about buying it for some reason.)
Other current options are to try out something else, out of the delivered mattress options the OTTY seems to be the one that appeals the most or the Inofia mattress from the rainforest as they still offer the 100 night trial and reviews are very positive.
Backup choice is to pick up an mattress from Ikea but only the cheapest HOVAG is available currently, I presume due to the stores being closed.
I'm sure the consensus will be to get the JR but any other advice would be appreciated.
Even if you went for the premier inn bed, I think the lead time on it is well over 4 weeks. Same with a brand new JR bed, you'll be waiting 4-8 weeks, maybe more.
A clearance JR mattress is the only way to get one in 2-3 weeks time. I bought one myself for that reason. I think their grading is overly optimistic - the one I bought was pretty dirty and had black scuff marks all over. I think if I was getting this in a showroom they'd knock 50% of the price off. I did manage to clean off most of the marks but it wasn't what I was expecting for "B" grade. Otherwise the mattress was fine.
Buying a mattress online is pretty hard - I think at some point you just need to go for it and expect a good chance of having to return it. I'd phone up or email JR if I was you and they can give you more advice on what mattress to pick. Me personally, if the shops were open, I'd go to John Lewis and Ikea and try out all the mattresses in person. Once I had a good idea of what kind of mattress I like (foam, latex, inner spring, firmness, and topping), I'd compare it with JR mattresses and choose that way. JR has a really great return policy, so that is why I'd lean towards them, even if I think they are priced a bit higher than other retailers.
If you like the premier inn bed, you might find the JR mattresses tough to get on with initially. Their filling is overstuffed, like other high end mattresses - which means they have these firm bumps all over the top, until it "beds in", which means the filling flattens out. You may need to factor in purchasing a topper to make it feel similar to the premier inn bed. John Lewis sells good quality toppers, both synthetic and more expensive natural fiber ones.
All the foam in a box companies have really high return rates, but they are a risk free option to try. You could go for the OTTY and see if you get on with it. Keep in mind though these foam beds are made from low density foam and just aren't supportive enough unless you're light <80kg. Most people return them for being too soft. John Lewis has the Emma mattress in store so you can try it out beforehand when they reopen.
JR articles are not very positive on Ikea mattress. However lots of people have Ikea mattresses and really like them. I actually have a HOVAG myself for my youngest. It's surprisingly comfortable. But if you look at its construction, by all accounts it should be "terrible" - low spring count, thin topper/filling. It's not particularly luxurious, but at only 180 quid it's not a huge risk either. If not picky about your mattress it might suit you fine. Keep in mind you can't return mattresses to Ikea, only exchange them.