I'm not a computer genious or anything, but I'm going to say that the $750 one is faster than the $450 one. It depends on if you value your time that much.
I'm in the boat where I'll spend another $500 on a laptop to get that performance if it saves me 10 minutes a day waiting for stuff to load up.
COMC Auto-Accept Set at 20%
Lots of [???], [Missing] and #N/A at ROCK BOTTOM PRICES!