This was a great little arc. I'm surprised it hit so fast and so hard, but John Ostrander always did plot tightly back in the day and Gail Simone clearly writes in the same style. The two work really well together. The Squad and the Six are spot-on.
I really enjoyed seeing the Squad shocked at how much Deadshot fits in with his new crew. I really think Rick Flagg and Amanda Waller thought Deadshot would come strolling back to their ranks and leave the Six, but Deadshot put an end to that thought with his "no thank you" to Waller. And by "no thank you" I mean a shot to the chest. I did like that Waller still thinks there is a good chance she could get him to sign on later if she had to anyway, so if there is another Squad series, I'd say Deadshot could be a part of it.
The story fits in nicely with recent DC history too. There are numerous references to Ostrander's most recent Squad mini-series and we actually find out who Mockingbird is! It's an excellent choice. All the Blackest Night stuff was incidental, this was all about the two toughest teams of scum in the DCU.
Jim Caliafore isn't the hottest artist around, but he's solid. I do hope we get Nicola Scott back on the Six. Not many artists bring her clarity of emotion to these tough characters.