The first half of this film was full of long shots and poses with little dialog. The action started to pick up toward the end, and I expect Part II will be action-packed. This is consistent with the book, which was also lengthy and slow.
I found myself looking forward to the Doyle-esque internal monologs that Holmes had, as he sized up his opponents. Unfortunately, far too much of the film was gratuitous action, not thoughtful dialog. It was a worthy interpretation, well executed by the cast, and is worth seeing.
I guess with an "R" rating, you probably wouldn't take your kids anyway. One of the best adaptations of a DC Comic that I've ever seen. It's long, but rarely boring. Some good comic lines. Some very graphic stuff, but I didn't find it objectionable. Seems like Watchmen would appeal to males, 18-50+.