I've never really played much with Mageia since the live USB never wants to run right on either of my computers. I don't know if it's because I use unetbootin to write the iso or what, but the liveUSB never seems to run right, so it's very hard for me to try out Mageia.
So I can't really comment on it, but have heard it's an excellent alternative to debian-based and ubuntu-based distros
Don't like Unity? Hate it? Not your cup of coffee? Ubuntu does provide choices. There's GNOME Shell, KDE Plasma, Xfce, LXDE, and now MATE and Cinnamon. Take your pick