Coming from a blackberry, and the prevail. I love the ultra, super fast, great screen, and root!
The only problem(s) I've had with it was the dragging/dropping issue and an incident with the glass on my screen wasn't adhered very well so it started to separate from the phone. Waiting on samsung to repair and send it back.
Overall, I would definitely buy another. The phone outperforms other phones in numerous benchmarks (due to the lower resolution maybe?). Very happy with it.