First off, let it be known that I run pc and plan on sticking pc for quite some time.
To be honest I didn't even check in on the specs of the Asus, but pc laptops seem to just blow in comparison to mac laptops. I picked up a laptop with comparable specs to my desktop, except it's dual core instead of quad, with the intent of having as an on the go editing computer; something I could do rough cuts with while I'm traveling. I understand that with it being dual core and not quad it wouldn't run as quickly as the desktop, and i knew that, but this thing can't do anything when it comes to video work. I'm running the adobe cs4 production suite and it literally can't handle any video. I don't get it. Then I compare it in performance to a friend's macbook pro from 3 or 4 years ago, and it can handle most things thrown at it, slowly, but surely. I actually just looked briefly at the specs of the Asus and gaaahdamn. I don't see how that thing wouldn't be able to handle just about anything. That is a beast of a laptop. Perhaps my experience won't apply to this situation.
As to the question of Premiere vs fcp, they're very very similar. I honestly think Premiere has an edge on fcp right now, but some people will give you shit about it not being the "industry standard". Being someone who has pretty much always used premiere my view may be slanted but I've tried to keep an open mind to fcp. It's an amazing NLE as well but when comparing features I find that you can do more within Premiere than you can within fcp. If i were to switch to mac I would definitely still stick with my adobe production suite.
If you can spring the extra cash I would say go for the reliability of the macbook pro, although if you know anyone with the asus I'd say talk to them and see what they think about it. It seems like it should run like a dream but with my experience I've become wary of pc laptops. Just my two cents on the situation.