Define stable. I found it stable enough, but half my apps didn't work in one fashion or other, it got so hot you could fry an egg on it and the battery life sucked. It also got so slow you had to reboot it several times a day so it was at least usable.
Stable though? Sure.
I would tend to disagree about the apps - mine all work fine, although I suppose it depends on what you're using. In terms of stability, it's so-so. The OS itself hasn't crashed, nor have I required a reboot, but I'm having problems with cellular service; phone calls will regularly cut off and messages will often fail to send. Aside from that - which I am able to put up with in the short-term until the next beta - I've got no problems with it.