I would be slightly worried about thermal throttling. It's nice that they can put i7 in these, but as they are slim, they have either really little fans, or just passive cooling. That might end up by CPU trying to save itself from overheating by limiting it's power. I'd go to a shop and try some CPU burn test on the machine beforehand. Also as Marrow said. Make sure you buy a lot of RAM. Especially if you intend to use some big sampler patches/libraries.
Also, I too went for gaming laptop. They are cheaper in build, but good bang for a buck as far as power goes. ...and they can usually cool themselves relatively good.