I'm not sure which model is, but a friend of mine has a Samsung Android (just got it earlier this year), and it's incredibly slow and clunky feeling. Apps are always crashing, the operating system seems slow and laggy, the camera takes forever to take a photo, among other things.
The iPhone 4S is hands down the best phone I've ever used, in my opinion. Again, not hating.
I have a samsung galaxy s2 and it's rad, it's so fast. The only downside is it comes with Samsung's shitty TouchWiz on but I put a custom Samsung ROM with TouchWiz and all the bloatware apps on it removed and now it fucking flies. I was gonna upgrade to the Galaxy S3 this year but there's not much point, I'm going to let this contract run then look at my options.
I did a restore by accident the other day and went back to gingerbread, fuck me it is slow as shit compared to ICS, maybe it's because of TouchWiz or what, I don't know; but it was awful.