I've always been a fan of the Fading Suns universe, but never enjoyed the clunky mechanic of the 2nd edition system. The d20 adaptation is so much better! It takes the 2nd edition rules and helps to make them so much more playable and interesting.
The setting is very intriguing. Think Dark Ages/Medieval sensibilities merged with Space-Age technology. It's a fascinating universe to play in--very well fleshed-out even if you don't buy the supplements. As a bonus, if you don't like the d20 Modern/Future class system (which I don't), you essentially get new core classes and prestige classes. The Magic system is modified, too, and fits in well with the setting. The only gripe I have with the universe is that only Charioteers (guild pilots) know how to pilot ships--this isn't Star Wars where everyone gets a ship!
Anyone who owns the original rules will notice that most (if not all) of the art is the same ... except for the excellent Brom cover.
I would have appreciated some starship combat rules, but I have played Noble Armada (Fading Suns' starship combat game) and didn't like it. I'm figuring out how to integrate Starmada and Silent Death rules, which are much more streamlined.
All in all, among d20 Sci-Fi core rulebooks, this one stands out as the best I have seen so far ... compared to the revised Star Wars d20 core book, the only thing it is missing is starship rules and combat. Buy this!
[5 of 5 Stars!]