[obelix]

My experience has been horrible. I noticed bad slowdown in every app launching immediately after the upgrade. Apps took 30 secs to 1 min to launch (twitter, lose it, even calculator).

It progressively got slower. Keyboard response ground to a halt. It would take 3-5 secs for the keyboard response to show up on screen.

It became an useless paper weight.

I tried restore to 3.1.3 a few times and I would give up at the 1015 error and restore back to 4.0, which was probably a "clean" install. It didn't fix it.

The primary feature I was interested in was the orientation lock which is not available in iPhone 3G. Threaded email is nice, but not a deal breaker, same with folders.