I still play, every few months or so, just to check on it.
What I've noticed is bringing the servers from 16 to 8 players does improve play-ability, but people get more easily annoyed and quit quicker than usual now, because when there's only 4 people on a team, they're going to get killed many more times than before in a shorter period of time.
The guests can get...annoying. Because they're almost all total noobs, and sometimes comprise your entire team. And often I've seen them just bouncing around in the base shooting at each other, or placing shocker shields inside for the entire match
Didn't it used to be that guests had to join before playing in multiplayer matches? Might be remembering wrong.
I still notice that occasionally, I am randomly booted out of a match without any warning, like instantaneously while killing someone I'll just be back at the menu half a second later.
What I think would be cool, is if the training arena that you see at the start with all the AI players,
was added as a multiplayer map.