I managed a lab of them. I _hated them_. They were unreliable, slow, and just absolutely miserable because they created endless complaints.
We were rolling out labs of Windows machines. Except for the lack of terminal, they were better on every single axis for the common university lab use cases - mostly netscape/mosaic and applications..
I also managed NeXT slabs and cubes; they were vastly better than the sun boxes because we had installed HDDs in the cubes and extra memory. The only problem with them was the absolutely terrible, shit behavior when users accidentally browsed the AFS root...
The only positive thing I can say about those Sun boxes is that _one_ behavior was better than NeXT. With NeXT, students would pull the power on them after wating four or five minutes of the beachball due to AFS I/O.
I remember a lab with diskless systems where your disk quota was smaller than the kernel panic dump. So basically if you crashed a machine your account was instantly filled up and basically nothing would work. I believe it affected mail as well. Fun times.
A younger person who only knows the comparative merits of Windows, macOS, and Linux in this decade probably cannot imagine the relief felt by people when they were finally able to move their technical applications off unix boxes onto Windows NT workstations. The situation was so bad, the computers cost so much and worked so poorly, a Dell with a Pentium Pro was like a miracle, at the time.