I've played a couple of 4/4 and 5/5 games time to join the game has much improved to something like 1 min maybe, about as long as it takes to join a DoW2 game (sometimes quicker).
I've never had a lag issue in a game, I have had a bit of stuttering where the whole game will freeze for like 10 seconds and it makes me think a crash is going to happen but the game so far has always recovered. This also does not happen that often.
A problem I am seeing is NAT faciltaion error. The window will pop up, I'll click okay. The game usually keeps going fine for me for X amount of time. This last game I was in 4/4 finished dispte that error.
Previously I was in a 5/5 game and the NAT error popped up, played for about another 5-10 mins and then game up and crashed on me back to the desktop.
Overall though after the last few days joining and playing games has been much quicker/easier. So IMO Stardock is making progress towards improving things.
There is only so many hours a week, yes they should have been more prepaired but they're a pretty new company and new to MP online. I can only imagine that the next game/launch they'll do better.