[wisty]

I've used them. They're pretty comparable to the average textbook. Maybe a few more typos than some 31st edition (which fixes a few typos and swaps the order of a few common homework questions so you can't buy the last edition) but it's ... fine.

There's some textbooks that have more personality. But the OpenStax books are pretty much the same as any other mainstream book (the kind that are assigned to most classes).

Maybe the calculus class was just boring? The textbook is there as a baseline to cover the derivations, example problems, and how to do them. I can think of plenty of reasons why a calculus class is just boring (too hard, too easy, or it's taught in a boring way).