Here's a handful of things I noticed while playing online:
I enjoyed playing against people with less predictable strategies than the AI.
ctrl+shift+buying an orbital structure allows too many structures to be added to the list
Players can edit the settings json to allow seeing the entire galaxy, it gives the player an unfair advantage.
Some asteroids gravity wells are too small to host twin fortresses and all their allotted structures.
It would be nice if the pause feature had some sort of timer associated with it, rather than being stuck waiting for an unknown time
When joining a game in progress (there hasn't been many opportunities for me to test this) It seems like it shows me the players and then assigns me one at random, and then starts the game before I get a chance to look and see if I want to join. It would be nice if I could see how long the game was in progress or what the situation is before joining. Or, be able to see the in game chat, and communicate, before joining.
At one, when It was just myself and AI players, I was running some CPU intensive programs in the background with the CPU clocked at 100%. Most of the time the game ran smoothly. When combat between two large forces began(1000+ supply), the game became choppy, and clicking on things had unpredictable results (such as rotating the entire map or zooming to another location instead of selecting a group of ships). I'm not sure if this choppiness impacted just myself, or would have impacted the other players.
I'm still not a huge fan of playing at default speeds, but I love playing with research, ship building, and income sped up. (Maybe one or two more tiers of it)
Anyways, I'm still enjoying the game and I look forward to the introduction of Vassari and Advent.
PS. having a 0% constructed starbase being destroyed while waiting for exotics sucks. Perhaps keep them immune from attack until they are being built. Or, allow them to get construction started, while simultaneously producing the exotics. If the exotics don't arrive by 90% construction, it halts production. I also like the idea of each exotic refinery maintaining a stockpile of 1 of each exotic. So, if you have 5 refineries, they would keep producing until 5 of each exotic are on hand.