Interesting review. I "had" LMDE 6 on three laptops but had trouble with upgrades from 5 on two of the three and then on going issues on all three. The worst problem was kernel panic on my daily driver, issues with regular upgrades and installing software from software manager on all of them.
I personally would not call LMDE 6 "rock solid". Of course, like everything, it comes down to individual experience.
Since then I've moved one back to Neptune Linux which has been a markedly better experience on that machine. The other two are still LMDE 6. One now works well but the other still throws up occasional update issues.
I love LMDE so I'm rather sad the latest release does not seem to work as well for me, as its predecessors. I've been using LMDE solidly on one of my main machines, since it was first released.
I will say I don't like Debian 12 Bookworm. I have tried it and had all manner of bugs on a pretty solid machine. So in fairness, i wonder if that is part of the problem here?
Never tried Ubuntu Cinnamon. I will say, I think aesthetically, it does a better job than Mint out of the box but the not inconsiderable stability issues mentioned, raise concerns for me.