Amazing Spider-Man is an on and off title for me. One issue will be really good, and the next issue will kind of suck. The reason for this is the amount of creative teams they have working on the title. This particular issue, has a number of different stories by all different writers and artists. It pretty much characterizes the whole run of Brand New Day, because I really, really like a couple stories and thought the rest were garbage.
The stories I liked, "Another Door," "Honor thy Father," and "You Again" were worth a $3.99 cover price I thought. Without spoiling anything, "Another Door" Brings Brand New Day to a close and perfectly sets up another long arc of Spider-Man to come. "Honor Thy Father" shows just who Harry Osborn has become, and "You Again" is a tongue-in-cheek fun story and a treat if you've been following Brand New Day since its beginning.
The other stories I was a fan of, but I wasn't too bummed because although the book was $4.99, I felt like the garbage stories really only cost me the extra dollar.
All in all, if you've been following the Brand New Day arc, you've obviously learned to take the good with the bad and will probably enjoy the final issue. If you haven't, just pick up #648.