I would love to go to this show and do have tickets for Summer Slam. But I just picked up tickets for a Ring of Honor show that will feature a couple of New Japan wrestlers. It will be Shinsuke Nakamura, Kazuchika Okada and The Time Splitters. Whichever event you go to I'm sure it will be an awesome weekend.
On one hand NXT is an incredible show. On the other, you'll eventually see a good amount of the current NXT brand on the main roster and will have few opportunities to see NJPW wrestlers locally.
I'd have to follow your lead and head to ROH. That should be a special show and a hot crowd!