I'm currently running LMDE 2 and will upgrade to something newer in the next couple of days.
When I first switched to Mint from pure Debian, the main reason for it was that I hated Gnome 3 and wanted MATE. Now the situation is reversed: LMDE does not offer a MATE installer, while Debian does.
- I am sacrilegious---willing and able to install codecs and some drivers from the Debian non-free repo;
- I do nearly all configuration from a terminal; and
- I do all updating and backup from a terminal,
is there any reason at all to go with LMDE over plain Debian?
Edit. I suppose, for others who may have a similar question, that I should mention that I did hint at a couple of features that the Mint version offers (easy proprietary codecs, the Update Manager, and backup and recovery tools; some of these things might be in the current version of Debian---I'm not sure).
Edit 2. The default sources for LMDE 3 are as follows:
deb http://packages.linuxmint.com cindy main upstream import backport deb https://deb.debian.org/debian stretch main contrib non-free deb https://deb.debian.org/debian stretch-updates main contrib non-free deb http://security.debian.org stretch/updates main contrib non-free deb http://www.deb-multimedia.org stretch main non-free