Hi!
-All Factories-
Advantages
* Planets can build ships, factories and do research at the same time.
* It requires low amount of MicroManagement. After the second or the third factory is built, player sets focus on research and forgets the planet again.
* Easy to do an early low-tech attack, where only transports and very few armed ships are needed.
* Easy to do the mid-game attack, since most planets are developed and can produce lots of cheap low-tech warships and transports. The added bonus is tech, gained through invasion, that can help overcome the tech lag.
* Initial Colony now has production of 16 (DA 1.6 beta5), allowing faster start of a colony.
Disadvantages:
* You don't have much to sell to get more money to sustain planet ramp-up.
* "Fastest" tech is almost mandatory.
* Obtaining both extreme colonization techs is necessary, as it effects only output of factories.
-All Labs-
Advantages:
* Lots of money earned through tech trade.
* strategy-supporting techs (diplomacy and econ bonuses, better labs) can be gained very quickly.
* independent of the development of other AIs. The only thing needed from them is money.
* Second part of extreme colonization techs can be ignored, since it effects only production of factories.
Disadvantages:
* Not possible to build labs and ships at the same time.
* Hard to compete with AIs in colony rush on maps with lots of planets, since no planet can dish out any serious amount of military production. This results in realy high costs of colony rush, since most colonizers have to be bought, and that takes away another big amount of money from already low treasury.
* Playing it without the tech trade "on" makes it exponentialy more difficult.
* Constant trade tech-for-money and buying takes A LOT of MM.
* Susceptible to an early and mid-game attack, as its military production is still low.
* Requires rebuilding of planets with factories when target techs are researched.
-Comparison-
* Both strategies demand lots of money, but all-labs is more demanding, since the first lab or two on each planet have to be bought, and also most colonizers.
* IMO all-labs is more appropriate for smaller maps, and probably can't be played without tech trading "on" on obscene and suicidal.
* All-factories is more appropriate for larger maps, as planets can build and research at the same time, so player's costs for colony rush are significantly lower.
* Both strategies suffer with the "slow" and "very slow" tech settings. All-labs because it can sell less, and all-factories because it can research less, but the all-fac's is hit more.
My 2 cents.
BR, Iztok