GameSpy has posted their review of Sins of a Solar Empire: Rebellion!
“Rebellion doesn't stop there -- nearly every system in Sins has been modified in some way, most notably the Diplomacy research tree. It's now far more useful, thanks to faction-specific researchable bonuses that unlock for both you and an ally. And the pirates, which conduct raids at fixed intervals against the player with the biggest player-set bounty on his head? They're much fiercer in Rebellion, and not to be trifled with early in a game.”
Read the full review at GameSpy!