I picked up both Flashpoint #5 and Justice League#1 and as to the latter, would have to agree with CBR's review of the book. It was better written than I thought it would be (I'm saying this as a big Johns fan) and Jim Lee is at his best. Justice League has more of a feeling of a team up book than us being introduced to the world's greatest heroes.
As for Flashpoint #5...man was this whole thing disappointing. The pay off comes at the end where Bruce and Barry share a nice little moment together. The transitional pages are pretty lame to me, oh and Thawne explains things in this issue. I think I'll be passing on picking up the hardcover when it comes out in Oct.