Re: Centos & Mint
Mint 17.3 (released January 2016, based on Ubuntu 14.04) is LTS until April 2019. Mint 18 (to be released May/June 2016, based on Ubuntu 16.04) will be LTS until 2021. It's a bit close and a big overlap.
I got Mint 17.3 installed and hammered into shape at the end of January. After that exercise I'm going to wait at least a year before trying Mint 18.
(I was quite happy for three years running Mint 13 which is LTS until April 2017.)