Yeah, its one of the best buys for that budget. Unless if you take the Lenovo Y510p (Single GT750M) into consideration and then get an external one later

(1) If you are not into photo editing, rendering, tedious photoshop tasks. The i5 will do, regardless of its generation. It saves more power too

(2) The "ultrabay" concept was pretty popular in Business line notebooks i.e. Fujitsu during the earlier days. But implementing it in gaming notebooks brought about a different level of versatility. You don't just put in a 2nd GPU, you can put in other stuffs like a fan, optical drive etc. The GT750M SLI will perform better in games (that are optimized for SLI) as compared to the GT60

(3) MSI is not really popular until very recently, gaining momentum along with Illegear, whereas the main gaming brands starts to "shine less"

If I were you, I would go for the MSI, specs ain't everything, and if you really like the keyboard, that's one more reason for you to go for it