I remember in mid 90's trying some of them for the first time. I've got really impressed by Sun sparcstations and IBM Power machines. Computers which you could spend the whole day programming with no threat to system stability, even after consecutive segfaults, impressed me. And it impressed even more knowing that in the UNIX world it has always been like that. Seeing a x86 again running windows felt mostly like a toy after that. Certainly one of the reasons that influenced me to use linux.
Those machines were expensive. In the range of a tens of thousands dollars. So, working on one of them was a symbol of status and success. Owning one of them, to me, was like owning an yacht or exclusive sports car.
One thing I like about cheap ARM SBC's these days is their performance... these machines have a performance, that I think, is similar to how those UNIX would feel. Linux is way more advanced than those old unices but the feeling is still there. I can install wmaker and get a very interesting nostalgic feeling.
Just to try it, I installed the latest CDE version on my experimental Debian 11 system. It is incredibly usable and performant. Being able to have a well integrated system, with everything needed for development was just another level in those days. While on the PC people rejoiced because of Delphi and Visual BASIC, you could write real GUIs in C with CDE and application builder. I'm not claiming it is better in any way, but it felt incredibly more powerful.