Hi all, I have a relativley new Macbook Air (basic model) that came with El Capitan, and I now wonder if I can expect to upgrade to Sierra without any hassle? I don't really need Sierra, but thinking it might be nice with Siri and some of the other new features. This is my first Mac, and coming from many many years of Windows, I am slightly scared of installing any kind of updates or anything that could cause trouble. And this is a full OS upgrade... Thanks!