Flight looks very good. MS probably used a super computer to run Flight for that video. Once it's on the crummy PCs' we have to use who knows what it will look like.
Well a company like that has the money for them, we don't. On the other hand, FSX is the only one that still has performance problems five years after release and, like boeing247 says, they do not want a repeat. Today's current computers may not give top performance (as is the MS Flight Simulator way), but a couple of years later the computers start to get good performance out of it. Time will tell.

I've always believed that the demise of the ACES Studio prevented another SP, that could have given us a better performance boost with FSX, that is desperately needed.

Mark