343 should add a feature to the Game History page so that you can search for game records that you have in common with a certain GT. This would also allow people to find out who they play with the most. Or, say you want to find a game record, but don’t feel like going through several hundred (or even several thousand) pages of games. If you remember a couple other gamertags that were in the game, just type that in and it will show you all games that you played together in.
I think another nice addition would be to scroll through your session of games. For example you played 5 games today and when in post carnage report you would be able to browser back from game 5 down to game 1 of that gaming session.
Combined with your GT matching this could be a great way to up the statistics browsing features. I’d imagine the “groups” feature we never saw was much like your GT matching feature request.