I’m running Lion on a four year old MBP and never had any stability problems, not even with any of the developer previews. Safari used to behave strangely and still kind of does (once in a blue moon it will reload every single page you have open, which can be very annoying and even disastrous). That’s the most egregious issue I had with Lion.
OK, thanks. Looking back at the reports of instability, they all seem to have come from people who have installed Lion on top of Snow Leopard and seem to involve problems with the graphics drivers. I'll likely wait and see how ML performs before making a decision.
