You know, I might have actually considered giving SHIII/SHIV a try... if not for the decision of UBI to make a sequel to SHIII without ever adding controllable destroyers.
I'm at a loss to understand why they would "remake" the sim in a new theatre, leaving the sim essentially half-finished for MP purposes. I'm sure the campaign mode of SHIV is superb, but without human opposition in MP, I would shelve it pretty quickly.