Only ever had there foam type mattress and there only really goof for guest rooms i would say.As they do go down hill after a few years.
But never tryed there HÖVÅG mattresses given ikeas cheep and cheerfuller build quality cant see them being up to the main stream brands.Unless they are made and rebaged like others for example dreams own brand are made by reylon and reylon are cheeper.
I would say you can get better branded named mattresses if you look on line took me 2 mins to find a good site not the main stream stores.Most do free delivery with in a day or two.
I went this route for my main bed a few years ago got a superking size Miracoil 7 silent night mattress got it half the price of local stores saving around £300.
There are more than enough deals out there at the moment to get good quality at a good price so shop around
hope this helps as its a bit of a off track waffel