Coming from HTC Sense, and then briefly a rooted stock ICS experience on a Droid Incredible, I was shocked at how utterly awful TouchWiz is. On top of that, the Samsung keyboard is the worst I've ever used.
After a few days, I installed:
* Nova Launcher
* Swiftkey 3 (paid)
* Handcent
* Fancy Widgets (paid)
* Zedge (for some normal ringtones)
and now this phone is awesome. Samsung makes outstanding hardware, but they leave a lot to be desired on the software side. I mean, who releases a phone that doesn't even have an actual ringing ringtone? If you're new to Android, try out a few of the apps above, and you will see that your user experience can be MUCH better. Swiftkey 3 has a 30 day free trial, I believe. With Nova, you can edit the number of rows and columns in your screen, as well as giving you a scrolling drawer at the bottom.... so much better than TW.