I like the Blackjack II but the only reason I got it was for the full key board. I don't have and can't afford the internet and my aircard so I can't comment on the bells and whistles that go with it. I wanted to teather my phone as my modem but ATT said they could tell and charge me. When I was using my aircard with my department HP computer I seemed to have great "3g" service. Since I've moved to this DELL the service seems to be harder to reach.
I have had the BB Curve for 3 months now with Verizon and it's the cats pajamas. No issues, and as another selling point for BB one can go to crackberry.com and download free stuff ie software, ringers, applications etc. as well as purchase the better/bigger applications. Additionally, any user interface issues just post a help message explaining the issue and one of crackberry.com users will message within a few minutes.