I think on higher population planets the social specialization is better... On Terran and Ocean planets to have 700 like population.. The industrial spec does not give sufficient bonus I think to outmatch this high population. You need 3-6 levels of industrial thing to be useful, but still the trade port income increase is like 50%, not that much for that huge cost, but have to test it and see numbers, it is just my feeling that the higher population is better..

Actually if you build a ton of trade ports and upgrade alll planets to have industrial spec (not sure of the name) it can give a huge boost, though with decreased population, so you have to be careful.. In my calculation the first level is the best, that only removes 1-10 population from every planet, and gives a 10% trade port income bonus if I'm right.. but further levels decrease population by higher amounts and make the specialization not effective I think..

The specialization bonuses vary by planet type.  Volcanic and Ferrous worlds get much higher industrial specialization bonuses than anything else. 

Social Specialization is useful if you ever get Planet Corruption on a moon or asteroid. Makes it so the planet doesn't lose you money.

I'm going to play a medium map against easy AI without using any trade ports, only social specialization and see if I can get a decent economy.

I feel the opposite, i think they are equally good, as social spec. can easily give you huge number of extra credits (and extra pop growth), consider having a 700 pop terran as capital planet... you will never get this much trade increase from any planet.. and it was said before that there will be planets that are better in this, some will be better in industrial spec.

we will see how things turn out, after 1 day we cant say anything for sure..

anyway i hate being obligated to put trade everywhere if I want a good economy... there aren't much of alternative choices.. people say it will help trade economy better, this specialization system, but I think it shoud provide an excellent alternative to it..

Well I always put culture spreading buildings at my fronts to help me and hurt the enemy.

Agreed. Cultures effectiveness is not its small bonus, it is that if you have that small bonus on many of your worlds it do give you an significant bonus.

In my game I'm now turtling and building lots of specializations. My economy is going really well but boy does it cost to upgrade the specializations! It's a huge money and resources sink.

The social specialization is well worth it on high pop worlds, Plus it offsets the trade debuffs. In the end on Terran worlds you get a better income bonus than what you would if it had just trade ports. You don't need trade ports on those worlds unless you are trying to link them. Refinery's will be totally useless at max social. Like was said. It is better to use the low pop worlds for industrial spec. The opposite of social. Build shipyards, Trade ports, and refinery's for the build speed, and trade buffs.

I haven't seen all the planet bonus's yet, but in am liking what i see so far. Even if i do get a bad die roll, and they are all bad lol

On maps like Systems of War. I tend to use social spec on all but one of my home system worlds. Then i scuttle my homeworlds shipyards. industrial spec one of the desert worlds. Then use it for my shipyards. Social spec-ing the asteroids on that map may not make sense, but it is a huge buff for me especially if i am advent.

Check the income of a fully socialized Advent homeworld with allure of the unity fully researched.

lol, no, I mean on planets with low allegiance, social specialization may not worth it.. but not sure, haven'tt done the math..

I know on homeworlds this is brutal, I myself always use it.. (in that 3 games lol i have played with the dlc).

Heh, this is funny, cause we anticipated exact opposite to happen, the social path to be worthless and the industrial one be the sh!t. Who would not want better trade and faster ship production anyway?

Turns out the population increase is so major, at least for the high pop high allegiance worlds, that it outweights the trade penalty. I actually like that i have now a chance not to screw around with tradeports like crazy, this is nice especially for the Vasari, who get them later. Obviously it is bit more comfortable just to upgrade the planets instead of researching tradeports, building them on every planet, research cargo ships improvements, upgrade logistics slots on those planets to get more tradeports...

On other hand, the thing i dont like as much is. that both social and industrial path have basically the same main  implication - to improve your cashflow. At the moment its down to decide which path to use on which world to maximise your income, and thats about it. Would like to see some more differences.

Finally, i wonder if these upgrades have any inluence on the amount of money you get from stripped planet. I think when playing for VL, i wont be so ready to strip my homeworld as fast as before, given the fact, it equals to getting rid of 50 and more credits per second income now. Unless you OFC get proportionally more money from stripping the planet than before.