After getting back into Drupal 5.0 development, I have spent a lot of time ranting about how I find the most recent version of Form API hard to work with. People keep asking me what is "wrong and what to do about it. So far, I have not actually been able to articulate what really bugs me, overall it is just a feeling that I am constantly fighting the API and not creating code.
Having spent some time thinking about it, I think I am starting to get an idea of what bugs me.
Notes, maybe some day it will be a full document.