Neither. Manjaro [http://manjaro.org]. Well, it works best for me anyway. I've seen a lot of complaints about Ubuntu development becoming "sloppy" and I didn't think much of it until I used Manjaro. All the Ubuntu based distros I used always had issues, mostly when going into and out of sleep mode. Every time the computer woke up, some thing would stop working. Sound, wifi, mouse, etc. I just assumed Linux had a few kinks the user needed to work out. But Manjaro just straight up worked for me but minus bluetooth (I'll figure it out eventually). Linux distos are based on the same desktop environments, Xfce, Cinnamon, Mate, KDE, etc are all used by different distros. So long as you use the same desktop environment you learned in summer camp, you would be good
But that distro is Arch based and though I've found plenty of support for it, I can't say it has nearly the same amount of support as Ubuntu does. Since you asked Mint vs Ubuntu, I'd go with Mint. I preferred their desktops to Ubuntu and they ran pretty well and I liked their bundled software like Banshee music player. I agree with DoPo, KDE and Xfce are great desktops. KDE is sleek and Xfce is so fast and productive. You also might want to try ZorinOS. Its Ubuntu and its basically a Windows 7 clone so its easy for new comers, but it also looks cool and space-y