Budget and Location, I bet I could find a laptop that can beat both those HP's in performance and built quality
But seriously, what AMD is that? what exact model ?
and No, dual graphics isn't necessary better, usually more troublesome,
as for the 2GB Graphics.......it's usually useless depending on what GPU you're getting.
eg. GTX660M 2GB GDDR5 > GT635 2GB GDDR5 by a mile......
it's not the memory size that matters, but the GPU itself