Vacuuming was fairly easy. I wish I would have thought to wipe off the vacuum head before sliding it across my bed though because I ended up having to clean a smudge from a piece of dirt or something that was on the head.
I'm really not sure if disinfectant kills off dist mites, but I know it kills off germs and I was sick last week.

In any event, I just do that anyways because it's something I saw my mom doing when I was a kid so I figure it's part of changing sheets.
My mattress is probably around the 6 year old area too, maybe 7. Flipping has probably kept the mattress from having any ruts in it yet. That, and I usually sleep diagonally so my feet don't hang off, not always though. Some nites I curl up on one side because it's cold.
A buddy got a knockoff memory foam matress that was a "full" size I believe 3-4 years ago for $300. The mattress instead of being completely made of the foam, was a regular mattress with about 3 inches of the foam on top. I don't talk to that guy anymore and I don't know how long it lasted (probably still has it), but I remember when he got it and it was comfortable comfortable comfortable. If I'd had 300 bucks then I would have bought one too!