Blackberry user for years. I decided on the iPhone over the thunderbolt after hearing the crashing and battery life issues. This thing is phenomenal. After using BB for so long, it's hard to accept a phone that does exactly what it says it's going to all the time.
Honest truths, though, are that typing on BB was waaaY faster and easier, the email system was little better, I cry for BBM because most of my friends still use it, and weirdly enough I miss the LED indicator like everyone else here. Now I have to pic up the phone to see if I missed anything. All in all, though, apple has won my heart.