I played with one today at the local Apple Store. From a design point of view - it's very nice. The case feels VERY sturdy and I liked the keyboard and finish.
The performance appeared about on par with my Sentia M3200 - so I don't think that I will be jumping ship anytime soon. Besides, as Mr. Head stated (in his own way) why buy a Mac to run Windows?
I would like to see future Sentias have the same sturdy feel (especially as a business user/abuser). Also, I would like to see JUST the alien head on the cover (with the grips) - leaving out the big ALIENWARE. I see that the new SLI notebooks have only the head - which really is sufficent from a branding point of view. The Mac has the Apple logo only, and I think that it looks very nice.
Just my thoughts.