It looks like you'll be spending more for less if you purchase locally. If you buy online, who's to say shipping and or other charges won't work out to be the same. It comes down to what works best for you at the moment or later on; What do you want to spend, how patient can you be and how technically inclined you are.
If this were my choice I wouldn't even consider the warranty at all with my purchase. I have high standards that I expect someone else to follow if they are in possession of my belongings, since no one else will treat your things better than you, I chose to do my own "warranty" work when troubleshooting was required.
So what options do I have then, if I choose to avoid sending in for warranty work?
What I have noticed with most NB's is conditions. If purchased locally, internals parts that fail with a NB usually are present before the local return policy has ended. This makes it easier to replace the defective product with a new one since most policies are 2 weeks and up on electronics. When I purchase a NB, I undergo a series of tests and check everything under certain "conditions" so that I know it's working properly. This starts with a fresh clean slate of Windows and factory discs thrown out, updated drivers, stock BIOS and several games and programs installed while monitoring utilities are logging temps, loads, clocks, voltages.. etc. until the return policy has ended. I usually keep my system running most of the time and rarely shut it off or put it in sleep mode; On occasion, restarts. Various regedits and self awareness goes a long way in maintaining good system performance and OS stability. Some people find out things later on after the local return policy is up and some catch it before hand.
Online purchases just involve more time and possible shipping fees for returns until their return policy becomes the manufactuerers.
Attitudes. There are many people who are irresponsible and inexperienced with electronics that despite defective hardware and parts, warranties even exist. It's part of manufacturer tactics towards customers to entice their choice with them. Longer warranties and ease of it makes that one last resort option a godsend when all else fails. It's also part of a marketing strategy to give a customer that bit of a warm feeling knowing they are "covered" so that you purchase from them instead of the competitor who's warranty may be less in years (example.) Everything is this way right down to autos and miscellaneous merchandise. History of reliability cannot be compared to choice of realism and nature of imperfections.
So which would I choose out of the 2 you listed? The G750JX.
Benefits? The GPU really.
The 770m in terms of performance is similar to a mild overclocked 670mx on the VX. Gokica has had his 670mx overclocked to 1200 on the core meeting 7970m levels, however a 770m overclocked would yield even higher results than this.
What does this mean? The 770m model for the model price is more future proof than the VX model variant.
Since this is really about gaming delivery all while having something that looks sleek and while keeping price point in perspective when considering in purchasing a newer G series, it doesn't go without saying, it will have its share of quirks too.