Checkmate and Booster Gold are both great. Definitely read them.
Shadowpact is all right, but nothing special. There was an issue last month written by Matthew Sturges (the Jack of Fables writer) and drawn by Doug Braithwaite, and that was actually really good. Then it went back to Willingham and some other artist and it was just average again. Basically, without Sturges' humor and pretty visuals, it's not really worth reading. So I wouldn't recommend it (unless you really like Zauriel and Blue Devil, like me).
Birds of Prey sucked when I quit reading it, but that was about a year ago now, so it may have gotten better.