When I've been playing poker for 3-4 hours or more (last night I played a single poker tourney for 10 hours, and I got 7th place out of 205 players), the last thing I want to do is play cards and make decisions I just want to have a little fun at roulette.
Usually I only play BJ or roulette because I'm waiting for a poker tournament to start. I'm not too concern about improving my black jack skill so much I'm more concerned improving my poker skill. So far I'm up a little from black jack, and it's probably because I'm running good instead of being good. I use the hi-lo counting with 1-4 spread. I'm not a great poker player by any means, but I actually win some of these tourneys because the average players are so bad. That's because the blinds structure is really bad, and there are plenty of bad/drunk players. I mostly play low buy-ins (under $100) tournaments, commonly refers by poker players as donkaments.