Since i only play pantheon, this is what i have noticed. I play very regularly as you can see from my stats, i generally try to start 20-30 games each day, and have done so since the release. Few games actually start though, and get recorded in the stats. I have the port range 6000-6200 open so its got nothing to do with ports.
Pros:
When it works, connecting to other players are MUCH faster! What previously took 1-2 minutes(the "connecting to player x", now usually take 5-10 seconds! this is a great improvement!
Cons:
It works less frequently than before to find a game. i get "failed to get game info" roughly 3x as often as before, or some other strange error before the game starts, where i have to cancel and retry pantheon button. One of these errors is for example, the connection box pops up, but no players are listed. Didnt see these kind of errors with the previous patches...
Oh, and the dreaded "player have left the game" at the beginning of games seem to be back again... it was gone last patch and now is back again =/