I have a 22" Craftsman, for about 3000 square feet of lawn. I like it. It's quiet, takes up little space, and has no cord, gas, or batteries to deal with. Best of all, I don't need to have a shower and change my clothes after using it like with a gas mower! I don't find it significantly more difficult to push than a gas mower - a little harder than a light one and a little easier than a heavy one - and it's a lot easier to maneuver.
The main disadvantage is its poor performance in cutting long, stiff strands of grass. I always tend to wait too long before cutting though. If I made sure to do it once a week or less it probably wouldn't be an issue. It also doesn't cut very close to walls and fences, and obviously it's unable to collect and mulch leaves in the fall.
I think this is the fourth year I've had it. I haven't done anything with it except pull it out, cut the grass, and put it away. I don't cut the grass when it's wet though, and it's rarely humid here. My ex-girlfriend has been using an 18" Craftsman for almost a decade now and, judging by her lawn, it must be working fine. I don't think it's received any maintenance aside from the couple of times I repositioned the cutter bar.