as the main title says now, the preorders for the game are finally open, so if you interested...
i had the luck to be part of a closed beta, played first 5 missions of the single-player campaign and it definitely had the potential, well its not Homeworld and from certain aspects of the game you could feel its not a big AAA title, but for me, it was good enough. Last 2 missions brought even a nice story twist and change of pace to the gameplay, i rarely play single-player campaigns, but i was able to finish these 5 missions without feeling bored and annoyed...and wanted more!
Regarding hardware related stuff, although that beta - it was in february - contained few mostly gameplay related bugs and there was quite a lot of polishing to be done, it was pretty stable, no crashes, slowdowns or graphics corruptions. And in general it did not look IMHO any worse than Sins does.
All in all,personally, i am going to get it myself, despite already getting Rebellion. Will probably play GW more for its campaign (btw multiplayer/skirmish wont be available at the release, its supposed to be released one month later as free DLC though, - for though who are not into campaigns) and Rebellion for skirmish/multiplayer.