Two different systems (actually three)
Mint has to deal with cinnamon changes, nemo changes, mdm changes, etc etc etc and I noticed it comes down the pipeline once completed and tested (which I appreciate) solydxk doesn't have to deal with that part of it as they use xfce and kde unless they add more to it.
There not re-creating xfce or kde, or dolphin etc, so updates should come through quicker.
I'm actually going to install solydk on my mother computers, I think she'll love it and I only have to install it once
Which is why I love lmde.
Oh the joys of re-doing everything and making it better (in my opinion for what that's worth), I can wait longer for a nice cinnamon desktop