Finally gotten round to playing this and wow!
Real voice acting and moral choices that actually have some effect! Brilliant stuff!
My only gripe so far is that I'm getting the slowdowns too; I'm not 100% sure what causes it yet, but I do know in the first mission if I target certain fighters (Bombers in fact) the framerate drops to single digits, but if I Alt+T to clear the targetting box the framerate jumps up again?
I have a similar problem with Blue Planet and FSCRP Titan Rebellion. When I posted about it wrt Blue Planet, it was suggested there may be issues with the UV maps on some of the models which could cause this...?
But regardless, this is an incredible campaign; It really drew me in and made me feel like I was right in the thick of it! Stuff like this puts a lot of commercial games to shame!