Already been using surface pro 2 for one week which was bought from the opensurface(256GB/8GB). If you need to carry it around often, maybe you wont prefer this as it's quite bulky. The applications are running smooth and it's a very nice experience to use windows 8.1 with surface especially the snapview.
I havent install any games yet for the desktop version but i think it wont be a problem. I have tried the games from the app store like the ARPG Soulcraft and it's running smooth. For average, the surface can lasts for 6 hours per full charge.
As for rmvb files, maybe you can try the vlc player? I'm not sure whether it works or not.
According to the opensurface, the warranty for surface 2 in Singapore would only valid when it's launch here..
All in all, i am quite happy with this product despite of the weight and the pricey