I have used therarests, and current use either a Big Agnes Insulated Air Core Mummy for lightweight/size, or a first generation Exped 9. Both are fantastic. I don't think I can go back to uncomfy paper-thin foam pads ever again.
For the record, I do have a random deflation issues with the Big Agnes. Though, I am not sure it is actually deflating. Several times I have set it up, and it is still filled full in the morning. And several times I have filled it up and had it half-empty by the morning. Either the valve itself is leaking slowly (and tightening it up randomly seals it) or there is something else going on. I have a sneaking suspicion that the mat isn't actually loosing much air, but air/ground temperature changes are having an effect on the air density in the mat, and making it seem like it looses air. If that makes sense.
The Exped (old style) uses a stuff sack with a little valve to act as an inflation pump. Kind of a pain. But it works.
To those who cry about the inflation/deflation times. You are in camp, what else are you going to do? Seriously though, I have timed it, and I don't think it really ever takes much more than 5 minutes to inflate either of these. I think the inflation/deflation times issue is largely psychological.
They both weigh a little more, but, at least in the case of my Big Agnes, it rolls down into something the size of a can of soda. In addition, it has enough thickness to act as a little mattress, making sleeping on rough ground very easy. That alone is worth the little extra weight in my book.