Here is what I have experienced so far and I have seen other players complain of this as well in game.
1. Chat is unavailable when you die during a match and after the match is over. Limits being able to communicate during the game with other players.
2. You have to be careful when you die when you move your mouse or you will end up unintentionally selecting the wrong mech on relaunch.
3. Option to select an open server is unavailable. You have to wait in the queue to join a match. Left the game running and came back and would not let me in. Kept timing out. Relaunched and let me in shortly. Testing in progress.
4. Team deathmatch times have been reduced to 8 minutes. Matches are too short to really enjoy. Does not give enough time to come back.
5. Still need new maps. Possibly in further updates.
6. Noticed lag/jerky movement during matches. Not sure if this is the game itself or my settings.