I’ve had one for about eight years or so, and I like it very much. I got mine somewhat off price because it was a store demo, and for that reason it seems to have absorbed some wear that causes one side to leak air – slowly. So over the course of a week, and especially in cooler temperatures when the air is more likely to be denser, anyway, it will lose firmness if I don’t check and refill it.
But that’s no problem, as I simply reset to “my number” every evening when I sleep on that side (it’s a king size mattress, so I alternate sides, generally from month to month), and it’s not an issue. It’s the most comfortable mattress I’ve ever owned. (And even if it goes to a ‘zero’ value, it only takes a couple of minutes to get it back to ‘my number’. It never leaks ‘flat’, just ‘too soft for my liking’.) It’s not bothersome enough to even complain about.
If I were going to get another – which I’ve thought about from time to time – I’d get one of the ‘bendable’ ones and the supports to go with that to enable the different angles for the bed – but that’s quite a bit more expensive, and this one is very fine for now.