No, there are still features missing and lots of optimization to be done, not to mention lots of AI issues to sort out. I agree that the first 50-100 turns is OK to play and basically learn the game for now. It will (in my opinion) take about three to four month before I would consider it really playable, which is all features there, AI and game balance sorted out.
The main features that are not in at the moment are Espionage, Retrofit and Government. But in reality several features that is in the game is also incomplete such as Trade, Diplomacy and Economy... mainly because big parts of them is depending on those elements that are not in. This in turn make the AI behave like a complete idiot at times.
Some people do say that they have put in hundreds upon hundreds of hours and enjoy the game, I don't doubt these people at all. Personally I have probably played the game about 50-75 hours or so and every game has ended in frustration for one reason or another.
With that said I still come back and want to test out what's new with every major patch, because I do like the game even if I get frustrated all the time. I also don't accept that the game was released in the state it was but I will wait and play it for real when its done anyway. Unfortunately there are not that many companies who make these kinds of games so I really don't have much choice in the matter, or do I?!?
I have found two other interesting games that could potentially contend with SotS, one of them are going to be release relatively soon which is called
Legends of Pegasus, you should really check it out... especially if you were disappointed with this one or if you just want another similar game. I would probably want both anyway.
Another game that is in Alpha at the moment is Endless Space, another interesting game similarly to SotS 2.
So, in the end, there might be contenders out there... and if there is then Kerberos might have to clean up their act and at least release a feature complete game in the future.
If Kerberos fix SotS 2 to a complete and polished state and then release an expansion, I will certainly by the expansion... I still think the game is (will be) that good.