I had a couple blackberries for a few years (hand me downs, random upgrades my mom didnt take etc) and i loved it, swore i wouldn't switch, until i had massive issues with mine and then the replacement....I switched to droid and LOVE it even more, i can do so much more, its a million times faster (acedad is right, the advanced task killer is a must but its free!).
I have the samsung fascinate (verizon) and it is the best phone. One of the best things is at competitions, i can download the PDF of performance order right to my homescreen for quick access all weekend. A couple of very good friends have the iPhone and they are jealous of my phone, they love theirs, but want to switch..in general the droid is faster, better screen, can do more and the swype type is a HUGE help, one of the BEST features!