When we originally bought our superking bed from Ikea (about 20 years ago!) they advised using 2 single mattresses rather than one large one, though with a good quality mattress pad on top. I can't remember the reason, but possibly to stop sagging in the middle. We've also found the two singles to be very transportable, having moved house a few times over the years.
We still have the two original mattresses but have replaced the mattress pad a few times.
As I've been sleeping badly recently I'm thinking about an upgrade, and wondering whether to change the whole mattress this time,get 3 nee singles, or just to get another topper. It would be expensive to change the whole thing and as the bed is in the loft room, even if it arrives vacuum packed I'm not sure we'd easily get it out again.
Any superking gurus out there with some good advice?