I'm a late comer when it comes to iphones. Just received one last week for $15 dollars and so far i've been having an awesome time playing around on it. I jailbroke it and unlocked it. Unfortunately, i don't have the shsh for 3.1.3 so if I upgrade to ios4 I can't downgrade. So my question is, is it worth me updating? I've read people having trouble with battery life and other stuff when they've tried to JB and unlock with ios4. I've had good luck so far with minor setbacks while unlocking and jailbreaking my iphone. I'm mostly interested in the multitasking portion of ios 4 but dont' want it to slow down my iphone, or kill my battery life.