So you may have seen the Shadow Virtual Gaming PC on Channel5's The Gadget Show, this where i found about it.
Subsequently i opened an account and so far pretty impressed, it streams fairly smooth and once all setup i was playing within 10 - 15 mins.
The network speed on the VM is stupidly fast, my first game which was 55GB downloaded at roughly 50mb/s (roughly 500mbps), that is pretty fast!
The game ran smoothly on full settings, however as the game i was playing is a bit different than the usual (City Skylines) the graphics card isn't as important, all the work is done by the CPU.
The only thing i would say is that 12GB of RAM isn't much, and soon filled once some mods are added to the game.
If you want to give it a try then use my code below and save £10 off your first month.