I currently have a 3G, fw 3.1.3, jb using jailbreakme.com. It's working just fine...no issues.

I do like the native subfolders that Apple has come up with with the 4.0.1 release (better than having to use Catagories via Cydia on my current setup).

Can anyone point out any obvious pros/cons of upgrading from 3.1.3 to 4.0.1?

What could I expect in terms of perfomance? Would it "slow down" my 3G if I were to upgrade?

What would you recommend? Upgrade or just keep it like it is?

Any advice would be recommended. Thanks.