The first MS-DOS I used was MS-DOS 3.3 at the school computer lab, however when eventually I got my own PC, it came with DR-DOS 5, and the Gem inspired ViewMax.
I wanted to like viewmax, but I think Digital Research was short-sighted. They intended it to compete with dosshell.exe, but the real competitor was windows. I was excited to get to play with GEM, but I had no way to write programs for it.
I did GEM application development on an Olivetti M24 and various Atari ST models.
I used GEM on some PCs around 1990. At that time I had an Archimedes and was studying in a computer school. I did some DTP (a school magazine) together with a couple of classmates, and we could have done it on my Arch. But then they would have been out of it, so we used their more ordinary PCs and used GEM on them. It worked smoothly and was very responsive.
I used Gem on https://www.retromobe.com/2016/10/amstrad-pc1512-1986.html?m...
Felt pretty advanced compared to BBC computer!
Ha! I came to say exactly the same! I (my dad) had a PC1512, CGA with B/W screen. It came with a serial mouse that we only took out of the box when we used GDE. I have to say we didn't use it much, as we were used to DOS and the "I boot the computer and directly run the application/game I want to use".
My dad used Lotus 1-2-3 a lot (I guess that it was v2.2 or so in the Amstrad).