Nah. It was amazing back then.
My only experience with it was in 1999, I took a distance-learning class to learn C++. The teacher would send us mail about assignments, reading that we needed to do, quizzes at the end of a unit, etc. We submitted our projects through that system too.
Maybe I'd have a different opinion now, but I remember it working pretty well for that purpose back then.
Yeah it was sort of cool. There were entire software products built on top of Notes and its forms and workflow.
I never had to program any of that, so can't speak to that side of it, but where I worked we used Notes to quickly build a lot of internal forms and workflows, and had some internal discussion forums and documentation in it, it all worked pretty well as I recall.
The one weird thing was we had to run it on OS/2. The only OS/2 machine in the server room.
We didn't use it for email though.