Hi Dust:
The fat man loves b-2s. Great back yard plinkers. Probably best in 177 as not high powered. Don't see them for sale much anymore. South Summit still offers them, B2-245 at $38.95 so the price has gone up a fair whack but still cheap.
You can just open the box and wail away and it'll break in just fine or open her up and refine the innards to make her a sweet realy shooter. Should clean the barrel before firing, amazing amount of oil and swarf in some of them. I wouldn't try for more power, it's best kept as a sweet plinker. A good one can group to 3/8" ctc rested at ten meters. May need to touch up the crown though.
If you get bored, do a search for Cheap Seats, it'll turn up an overly long dissertation on tuning your very own B-2. Can't remember whether it's on AirgunGate or ChinaGate but it's out there somewhere.
Cheers
Fat Man
P.S. The B-1 is similar in a smaller size. Build quality was a bit rougher in my experience.