CCr is awesome, and Alien is awesome. Build quality and customer support are both top notch. You may run into short term headaches with Alien, but PB will take care of you.
CCr is campy, fun and a great shooter with limited code depth. Alien is dark, atmospheric with great modes and depth. What play style do you prefer? Pick the bright, funny game or the atmospheric, action game. You can’t go wrong with either.