Humm never player master of orion, but I'm a pretty big fan of 4x in general. I played galciv 2 and 3 and both of them left me kinda underwhelmed. They were workable, but got very boring very quickly. Tech just weren't interesting since for the most part they were just upgrade of previous building/space ship part. Building up planet is somewhat interesting in 3 since where you place building matters but it very quickly become routine, I think it would have benefited from building only being build able once with a larger variety of building. Combat was very disappointing, I see what they wanted to do, but they didn't accomplish it.
Overall I've never found a space 4x that had everything I want, most of them have little piece. Sins of solar empire has a great combat system, sword of the stars had great ship building, star ruler had great inter and intra empire trade system and so on. I've yet to play one where every system shine and complement each others.