Linux mint 18.x
I have two systems my IBM T500 mate desktop and a desktop (cinnamon desktop) I built. I have always like mint over other distros. I find thinkpads work the best not all will but I like the ease of upgrades if needed on these laptops.
The T500 runs fine once cinnamon is loaded but its slow to boot this is why I use mate.
My i3 desktop is great for cinnamon GUI. Its my work horse for many things. I upgraded to 18.3 without issue. Had a minor issue with the places app when I upgraded from 18 to 18.2 but fixed by updating places app.