I have had the Blackjack II for over a year now and I am extremely happy.
It's one of the most reliable Windows Mobile phones I ever had, battery life is pretty decent, very good call quality/sound, great keyboard feeling.
I never got rid of it even when I moved to the U.S.A. as I am using it with my plan for Canada (I am a Referee so I travel lots).
Overall, you simply can't make a mistake with it as it's a very good phone and one that it's easy to find parts for in case you drop it and scratch/break it.