If you lag at your house, the problem if your friends internet. I bet he hasn't configured the router optimally. Tell your buddy to optimize the WiFi channel on his router. It also depends on how old the router is. If the router is using compatibility to older cards, it'll cause lag.
I got JW version last year with the GTX765m. To be truthful, It runs cooler than the 770 (or 870 equivalent) version, so less power usage too. I bought my own 256GB SSD for 100 dollars on tigerdirect (MX100) and I kept the HDD it came with it on 2nd bay for no real reason (I should remove it. I don't even use it). The CPU is the same for all: 4th Gen i7. This laptop was, I think, $700 cheaper (maybe more) than the similar version you are looking at. If I were you, I would first decide what kind of gaming I would be doing and make the decision only on that.
If your definition of faster is CPU, then both are the same. If your definition of faster is higher graphics level, then are you willing to pay the price difference for playing between medium vs medium-high on Titanfall? (Leagues will run on max on either computer). And, are you willing to pay the difference in price for the SSD upgrade (today for $250 you can get a 512GB SSD).
