I had mx on an older laptop, but I never really used it much. I didn't have any trouble with it, but it seemed slower than Ubuntu on that machine (a Dell xps 13).
As for Mint, it was my primary work distro for about three years (2015-2018) on a 2014 iMac. I switched to it from Ubuntu when the kernel used by Ubuntu was taking 4 or 5 minutes to boot up the iMac. The older kernel used by Mint (4.08 and later, 4.15 as I recall) worked very well. Mint gave me no trouble and was at least as fast as Ubuntu. I used the Cinnamon version, and set it up to duplicate the look and feel of Gnome. My only complaint was the aesthetics; I like the look and feel of Ubuntu (and Gnome) better.
Incidentally, Mint is the only distro I have ever donated to. I was so grateful that it worked well on that iMac that I decided it was worth financial support.