Sword of the Stars has a barebones, but fully functional UI. It just takes some getting used to. (The 3D strategic map always does people in. )
As for SOTS2, well, there were a certain number of design decisions that made it an inferior product to SOTS Prime, IMO. Couple with an extremely buggy release (think Battlefield 4 or X3 Rebirth but worse), it soured many off the sequel.