The biggest reason is the $15/month unlimited data plan. Cingular wants like $45/month. Also, I live in the Kansas City area so I am just a stones throw away from Sprint's HQ, coverage is quite good around here. From what I've been told by people working for Sprint is we actually have faster EVDO in our area then the rest of the nation due to upgraded software/equipment... that could be a bunch of crap though.
I'll be honest though, I really do like the Blackjack, it's a tie between the two. The only downside is that it seems a bit smaller then the Q to me. I've toyed around with calling Cingular retention and seeing if they can meet Sprint's prince on the data plan to keep me.
Edit: I've also had a lot of luck with Motorola phones. I've owned two Nokia's and then three Motorolas and the Motos have been the best phones. My fiancee has had two Samsungs and they've been major pains. Buggy as hell. After the first one I'm not sure why she wanted a second, but she isn't a fan of Samsung phones now.
I love their monitors though.
