Hello there,
I bought the game mostly because of it's MP aspect, and after playing a few matches, I figured I could chip in my 2p here. Apologies if anything I post here has been covered elsewhere, I've tried to have a good look around the forum before posting, but nobody is perfect.

All matches have been played by two human players plus AI opponents over a LAN. Player 1 (host) has a Intel Dual Core E6750, 2GB of RAM and a GeForce 7900GS, running Windows Vista. Player 2 has an Athlon X2 4400+, with 1GB of RAM and a GeForce 7600GT, running Windows XP.
A pause button for Multiplayer?I'm aware that there are some DirectPlay issues that will drop players if no packets have been sent for a minute, but if there is some way to implement a pause function here, it would be very useful. It became obvious very early on that we would rather keep on playing than face saving and quitting the game for any reason, be it thirst, hunger, or a call of nature.
Date/Game time stamps on savegamesEspecially with the stability issues that we are experiencing with the game at this point in time, we make a lot of (multiple) saves, and often we don't actually remember which one is the latest. As far as I can tell, they don't get sorted in any kind of order (date modified etc.), so it's pretty much anyone's guess. A little something telling me when the savegame was made or how much gametime has passed at the time of saving would be grand.
Tech tree feels too... shortThis concerns mainly the late game stage on larger maps I think. Building laboratories is too cheap and too easy, since the amount of spare Logistics slots that planets provide is incredible, especially later on. Techs are really rather cheap, too, and we go through them too quickly. Often we end up accidentally building too many laboratories than are actually needed to research everything, and research things for the fun of it until it's all done. I appreciate that on a small map and a quick game the tech tree is just right, but on very large maps where you want more of a 4X feel, the tech tree just makes it feel like an RTS. Too quick.
To sum up my point: On a large map, once everyone is on the same tech level, the game turns into a slugfest. No technological advantage, no taking risks spending time and resources researching into one particular area.
A solution to that might be making laboratories use more logistic slots, or techs more expensive. Or just add more techs.
Speaking of resources - there's too much of themOn the one hand, the early game is great - very few resources, you haven't got much to go around, and you can't afford to waste anything. On the other, in our last match, a 5 System FFA, in late game we ended up with more resources than we could possibly spend, even if we had tried.
I feel they should be a bit more rare. Obviously, your home system should start out with resource asteroids, but does every single planet need two or three? Shouldn't resources be hard to come by? A bit more concentrated (like in an asteroid belt) and precious?
Again, I appreciate that on a small map, this works fine - rare(r) resources would spoil it, but on a large map, losses become devoid of any consequence. A player loses a couple of capital ships attacking another player? Nevermind, spend a fraction some of your resource mountain and you get new ones delivered straight to your fleet. You want them experienced? No problem, just another fraction of your resources and you're all set.
In short, I noticed I stopped caring when I lost a CS, and I didn't like it.
Interstellar Drive - Sun choke pointsI actually saw that this was covered in another post, but I figured I might aswell include my 2p here, because I think it's quite important.
Spam the Sun. That's all you have to do to defend your system, and all you can do if you want to take one. The AI doesn't do it as far as I could tell, which makes them quite easy to take out, but against a human player, it's quite hilarious. Hundreds of ships. More arriving from all over the galaxy all the time. Insane combat, crazy losses, and megabucks spent on construction (still not enough to run out though) - sounds fun in theory, but I felt that it was rather silly.
This was the point where our 5 System FFA ended prematurely - the moment where we started attacking each other. There is no way to get around this, no other way into a system but the Sun. Before I started realizing that you had to go through the Sun to get anywhere else, I was actually quite worried that I might suddenly get jumped by someone anywhere in my system, but all worries disappeared once I figured it out. Ships even get a bonus anti-matter recharge around the Sun.
Possible solutions I could think of might be to have ships actually receive damage when they orbit the Sun (it is hot), discouraging such behaviour, or allow alternative, perhaps slower travel from one Sun directly to a planet (MOO and EaW had something like this). Like it is, we almost consider this a gamebreaker on large maps. It's just plain crazy.
Anti-Missile ECM kind-of-thing?Nearly every new weapon in this game have a counter. LRM Frigate Missiles (to my best knowledge) don't, and hence become really rather powerful/annoying. A nice addition would be to give one of the Support Capital's the ability to jam missiles for X seconds, or give the Flak Frigates a researchable ability to shoot them down. Or both.
Performance and Lag in late stage MPThis is a biggie. Everything was fine in the 5 System, 10 Player FFA, until we went outside of our first solar system. The lag and performance got worse and worse up to the point where it seriously affected our gameplay. From being unable to watch combat close-up without huge FPS hits to the game taking several seconds to acknowledge a building queue, it was pretty bad. No problem on smaller maps.
Culture - To be or not to be 
This one is quite tricky I think. I do believe that culture is way too powerful - to be able to completely flip another person's planet without even moving so much as your little finger is nuts. The AI goes for it too slowly, making them pathetically easy to take over early on (house rule for us here is not to rush culture techs or spam culture). Culture also spreads beyond your own Solar System, and then on to planets that haven't even been explored/colonized yet, effectively stopping an expansionist player in his tracks because you can't colonize inside someone elses 'cultural border' (why not? the planet is flippin' empty, and if you don't like that, talk to my friend Kol over there), which makes culture spamming a completely valid and worthwhile strategy.
You have no defence against it save for your own culture, which may or may not be strong enough to prevent flipping. If you end up in a tight spot against a strong culture spammer, you have to build loads of broadcasting centres just to keep up. No options like lowering taxes or luxuries to keep people happy and prevent them from flipping. Military presence makes no difference, people happily change allegiance even if they know they are going to get blown up straight afterwards with absolutely no hope for help from the culture spammer. How do you take over a culture spammers solar system anyway? I'm scratching my head thinking about that, because it'd be quite impossible to get a foothold anywhere, since you can't colonize inside his cultural sphere. Do I really have to annihilate the solar systems population to reap the benefits?
Wouldn't it be better if *planets* spread culture from the very start instead of the broadcasting centres (they could "amplify" it instead perhaps), based on the amount of population a planet has. Instead of just wholesale flipping a planet and hence making it impossible to colonize inside 'enemy' culture, perhaps it could increase the risk of rebel incursion (maybe via Insurgency tech, an otherwise pretty useless tech), or make it possible for a Capital Ship to create an Insurgency via special ability (i.e. Incite to Revolt), or enable a friendly take-over (maybe just by putting up less of a fight when being bombarded?) of a planet once planetary defences have been dealt with. Something like that anyway.

That's all I can think of right now

. I really hope I don't come across like I hate the game, quite the opposite. There is a big chance that I could love this game, to fill in the rather large void that the lack of a decent modern MP 4X/RTS has created.
We'll keep on playing at any arte.