The Galaxy S3 and Note 2 run enough rings around any iPhone. Heck my GS2 and Note run rings around the i4s in my house.

If just smooth and fast are used as barometers, there is really no difference because after a point you can't see which is faster.

If you speak about jail-breaking an iPhone and rooting and Android device than the Android will always come out tops simply because along with the increased customizations you have larger screens that allow you to do more.

On both my S2 and Note I use multi-window, although it isn't too useful on the S2, its very nice on the Note with the larger screen. The iPad has something similar once you jailbreak it but the iPhone's smaller screen means its pretty useless to do any windowing on it.

The app gap is almost non-existent these days on Android; the last game I remember that made it big and launched on iOS without any Android plans was Temple Run. That too was quite a rare occurrence.

Android has its many flaws too, no doubt about that, but choosing between an Android device and iPhone its always wiser to go for the Android unless the user is really a fanboy or not interested to tinker even a bit with the Android device.

The sales of S3 and Note show that many mass-market users who know not much are going for the larger, more functional and better-looking screens instead of the same old iPhone. Also let's not forget the micro-SD and replaceable batteries