I recently got a brand new 3G iPhone from the Apple Store after my old 3G stopped working. Like many others, I had "upgraded" to 4.0 and had horrible slowdowns. Luckily, something went wrong with the phone a week or so later, and I got it replaced under Apple Care with a phone running 3.1.3 Everything was fine for a while. Now I'm having weird issues that even Apple Care tech support is getting stumped by. Not really worth going into here, though. My question is, how well does 4.1 really work on a 3G? I want to do a restore on the phone to maybe fix some of its problems but don't want to have a slow phone like I had under 4.0. Tech support claims 4.1 is fine for the 3G, but I'm suspicious. Anyone care to share opinions on how well 4.1 works on a 3G? Should I "upgrade" again? Thanks.