As of yesterday it is unplayable for me. I was one of the people who was able to connect to matches prior to the patches in any mode (skirmish, custom, pantheon).
Yesterday's patch has med it nearly impossible for me to connect. I don't play custom games very often so I didn't try that out last night. I did try both Pantheon and Skirmishes last night. I got into 2 games last night in the hours I spent trying to play. The rest of the time was all matchmaking service failed, some other errors (can't remember the text), and a bunch of crashes. The connection process does seem like it is handling everything faster though. The rate at which users in the connection view was shifting through it's waiting, connected, not connected, etc. much faster. However, with that it definitely increased the rate at which errors were being thrown in my face. Errors that were not happening to me prior to the patches.
Prior to the patch it would take a few tries (1-3 on avg) to connect to a game (pantheon), but I was playing games consistantly. Now I don't even remember how many tries it took to finally get the 2 games I got last night. And as for those 2 games, well the first was a total of 5 people, the connection process eventually kicked one of them and the game started. Unfortunately, for the me the player that didn't get in was on my team and I ended up having to play against 3 people. The 2nd game was 3v3; 5 players made it into the game. Shortly into the game one of the players got booted, then shortly after another got booted, then the worst happened, one of the player desync'd causing the stupid desync dialog box to come up as someone previously mentioned.
Now I understand that you are just looking for feedback on the connection process which is why I understand that the desync is possibly something that needs to be looked at by another team. My concern though about the players being booted out while in the game (and even the desync) is that possibly the connection process failed in determining if the players could even connect to each other properly. Like a race condition maybe. Because if you look at the connection process happening live you see people shifting status as connected, not connected, waiting, etc. I think that it is possible that now that the process is sped up some false positives may be happening and if the timing is right the game thinks people have then connected to each other but really haven't resolved their NAT connection to each other. Then once in the game people start getting booted because their connections are not communicating and then eventually leading to a possible desync as well.
In reading this thread it is interesting to note that people that were having problems prior are having more luck but people that weren't having trouble before are now hosed (there were a few posts in between that spectrum). I work for a software company in the video game industry myself and we have a p2p system. I can sympathize with you on the difficulty of getting it to work properly. It is by no means an easy task so I thank you guys for all your hard work on this and look forward to a resolution. I'll likely try my luck again later tonight or tomorrow and hope that maybe I was just running into an unlucky run of people.
Thanks again for the hard work and late nights. Great game.