It uses a custom Nvidia graphics card with unknown specifications and drivers. For a PC, I don't think I could trust that.

While the processor (now two generations old) is plenty fine, I'd be wary of driver support and limited ports. For the price, it's probably not a bad deal, but if you're going to make the push to a desktop for gaming, you'd probably be better off getting a custom-built one, or getting a desktop with a decent processor, then buying a new power supply and getting a better graphics card. Usually better in the long run, and MUCH more upgradeable for the future.