The TEC star bases are may be the best ones. They can not move, like Vasari star bases, but they have some unique useful abilities. Every star base may have maximum of 2 weapon slots, 3 armor slots, 3 fighter hangars, 2 trade posts(yes additional credits for the empire). And the TEC have special 2 construction yards(very very useful), 2 repair slots, a self destruct and an auxiliary control. Last two are not very useful. The last tech from the defense tree allow 2 star bases in a planet's gravity well. This base though is going down. But I'll be back there soon.