I can only speak from personal experience obviously, but I've had zero stability issues, and the whole data backup thing? There's an app for that
I have to agree with Midian, with my iPhone 2G I've had no 'stability issues' either, whenever a game's crashed on me, it's because of the game itself (where plenty of other, non-JB'd people have reported it also). I think outside of games, it's crashed to springboard about twice in the 3-4 years I've been using this device. Whenever I've had to backup data, I just use the app designed specifically for that purpose . Oh, and the whole piracy thing, in my mind, is akin to saying that anyone with access to the internet and a computer is a pirate.
Sooooo. I still have no idea what to do. Jailbreak or iOS4? If there is more to say, could you please put one of the choices onthe top of your post? Thanks!