How hard is this to do? Is it plagued with weird little problems that pop up all the time and is limited to only the bravest few crazy enough to try such a thing? or is it pretty common and user friendly? I know there are a lot of "how to's" on the internet, I'm just kind of wondering how common it is and if it causes much trouble for people. It's a build for my sister and her fiance as a wedding gift; he wants Mac, she wants Windows, neither of them are very tech savvy lol. Thanks!