Power, price (aside from this auction), availability, looks. I do prefer the looks of the 9000, but can certainly see why some prefer the G-9700 visually. I don't know enough about proper placement of circuity to know which one is better layed out, but can say that because something looks neater doens't mean it's better. Their may be a good chance it is, but I don't have the electronics or circuit design expertise to say. I can also say that weight doesn't mean everything, so something that weighs more doesn't mean it's better built. Call me crazy, but I can't judge the overall build quality based on looks. Unless there is something obviously awful (1"x2" heat sink on a 400w amp or something to that effect). I'm not saying the G-9000 isn't superior to the G-9700, it from all accounts appears to be, but I'd like to know more about the basis of those comments. Looking at a pic and seeing nicer capacitor covers inside doesn't make me think "wow, thats a lot better built".
I hope Glenn can comment at some point and address what he believes makes something good quality vs average.
That might make a good thread on it's own...