Oh, also, if the Sager I had configured had no additional AC Adapter, some people say it matter, some say it doesn't. It's an extra $250 bucks that I'm not sure about.
It has to do with the system needing a ton of power (happens when you mix desktop processors with dual GPUs). Supposedly, under high stress situations (FurMark benchmarking for example) the single adapter can't supply enough juice. I'm not sure how big of an issue it will be with games and applications since Fur Mark puts a relatively unrealistic level of stress on the system. Best advice: Call the people you are looking at buying from and ask them. Otherwise, go to the Owner's Lounges at either XoticPC's forums or NBR's forum and ask their opinions.
I don't know though, alienware really catches my attention, besides being 18" I like the design and all... Tough choice, guess I will decide on the better GPU.
That's what makes it tougher. If you look at the benchmark site I posted earlier, the GPUs are really close. When either loses to the other it's only by a few FPS and it's certainly not something you are going to notice. Buy whichever tickles your fancy.