Mint is one of the greatest distributions to get started with for users coming from Windows. I've been using Fedora full-time for more than four years now, but before that I used Linux Mint for about a year. It's a great, seamless experience.

Only problem I believe is the lack of customization options in Cinnamon compared to KDE and even Gnome with extensions. I guess that makes the user miss out on some of the cool parts of owning your software. Also, being stuck in X11 will start to become a problem in the next few years: I'm waiting to see what they come up with on that front.