I would have to say 2 civs on advent you reduce the time of research on both military and civs, and get started on the culture

on tecs, you can get started on the trade ports which would provide you with extra credit, not to mention the metal and crystal production rates increase

This is very dependent in multiplayer games. I tend to hold off on building them purely because I want to scout enough early (I get 5 and have them all scout, except as Vasari I get three). You need to know what you're dealing with before you do anything.

If your opponent's asteroid or homeworld (Which ever is closer) is 2 jumps or less, get military labs and rush him because in multiplayer he will almost certainly be rushing you.

If he's 3 jumps away, that's the iffy territory. You probably can get an econ going (like say a culture station, maybe ice and lava teched, NO TRADEPORTS IN FIRST 15 MINUTES). Then build a fleet and go after him. You can't let him linger too long. Ideally you can knock out his frigate factories with a surprise attack and nail him to the wall.

If he's 4+ jumps away get two civ labs. You're going to get a decent econ going because you'll easily have 4 planets before he can get near you. This is where the fun begins because youre econ will grow and you'll get a huge upgraded fleet OR give your ally a ton of feed so both he and you have a kick ass fleet.

+Karma is appreciated!

It definitely depends on the distance between you and your enemy.  Going civic when you're 4 or fewer jumps away from an enemy homeworld is quite dangerous.  On the other hand, there's largely no need for military labs early on if he's 7 or more jumps away, since it's virtually impossible for him to attack you.

As for a civic/military combo, the main reason you don't see this very often is because you either attack or you don't.  Going half-and-half is usually a sign of indecision.   There are a few reasons you may consider it, however.  Vasari obviously have the best reason; this gives them access to assailants, basic combat upgrades, and population upgrades.  A great balance of econ and military that's relatively low risk, and a great way to open if you're in that "iffy" range that Amish talks about.  They don't need two labs immediately; you can delay sentinels in most cases.

For TEC, this gives you access to your population upgrades and your repair bay.  I'm personally a fan of the "ninja colonization" technique where you capture the planet out from underneath the militia (after destroying the siege frigs, of course) then put up a repair bay.  Of course, in the general case you want to get those LRM's out asap.

I don't think there's a good reason for Advent to do this; I either go straight for 3 civvy labs or 3 military labs, rarely a combination.  The progen is your best economic investment, anyways.

While that's a decent rule for beginners (I've seen too many people rush out those trade ports and have no fleet to defend them) I think there are better rules of thumb.  The one I follow is to only put up trade ports once I am able to build a significant chain (at least 3 nodes, preferably 4).  This means that I'm in relative safety, and I have plenty of cash lying around to put up the infrastructure.  This can happen before the 15 minute mark, it all depends on the situation.

With that said, I can't agree enough that it's a mistake to put up two labs and research trade ports at the start of the game.  Colonization and capturing neutrals is far more lucrative and less costly.

i never scuttle my cap-ship factory,  cuase my nextcap-ship is never far away

building research stations dependso n the game,  map-size, recon etc.

if i c an advent player building up 3 temples of hostilities i'd need a good explanation to make civ's instead of military

my fav. race = the TEC (lego's...)

as a TEC i build civ labs 90% of the time.. maybe 95%   the t2 tradeport is easy to get, and a must for quick-econ

as other races (i do play random occasionally)  80% being iviliain research i think....  upping your homeworld's pop-cap or getting rec's upgrades and tradeports rly works in the long-run (you do need to know when 2 switch for military though... recon + that feeling..)

on very smal maps (where i'll probably only control 3/4 planets max  military goes first,   having 1 extra ship over the enemy can mean alot here)