Instruct: Classify a given Amazon review as either positive or negative.
Query: good air mattress

Very comfortable air mattress. I've had several people sleep on it including myself - no complaints! Retains air for several days.. I think I refilled it once a week?? I really like that there is an inner and outer section to fill air. But I did find that I had to refill the inner tube more then the outer tube. After about a week, it seems like the the outer section retains air better, which means if there are 2 people in the bed, you tend to roll towards each other :) But its easy to inflate/deflate (though it does take several minutes) and stores easy. Comes with a bag. I like that there are no extra parts - that the wires/air pump are all built in. After some time, the sides do push out, and the sheets tend to ride up...so be weary of that. I couldn't find anything sheet wise, that makes this look pretty... the deep sheets work better then the regular ones. Also, keep away from the wall.. the knobs for inflate/deflate tend to rub against/scuff the wall..