I never liked Crossfire (1.9) for one thing:
Crossfire system. Mainly because it is -the only way- to the new sectors and systems + it's a nexus-like system.
Can't say much about CF 2.0, which I'd love to play our after (failed) experience with CF 1.9. I tried it run once - my PC heated like hell, FPS below 15 and ended up with BSOD. What the hell did they do with engine, I ask?