I'm currently running a jailbroken/unlocked 3GS phone on 3.0.1. It runs flawlessly, except that there are some programs in the app store that won't let me download unless I upgrade to 3.1+. Aside from this minor setback, I haven't found a reason to attempt upgrading and re-jailbreaking/unlocking. (I have ECID SHSH on file with Cydia just incase). I'm curious, how many others out there are running on jailbreak 3.0.x? Anyone feel strongly that I SHOULD upgrade?