I have the opposite experience. Sure, if you just need to adapt their examples a bit, it's quite smooth. But the documentation is horrendous! If you need to do anything non-trivial that isn't covered by examples, I found it very very hard to work with. The documentation barely exists and is written in poor English. Compare this to the documentation for ARM SDKs, for example! Night and day.

esp-idf worked on the first try.