CFAI text - subjects that are a MUST read over study guides

For the sake of time, If you had to pick and choose subjects to read in the CFAI text over Schweser or Stalla, which ones do you think are a must read? Thanks

None.

Ethics

Financial Statements Analysis and Ethics

i found it a must to read them all for level 1 just once, i am also doing the same thing for level 2 and i dont regret it. based on my timed reading from L1, I need 150 hours to carfully read all of the CFA books and i think is worth it… to me cfai books are as if you are attending a lecture by a charismatic prof, they are not well written to makes you remmber stuff, but they give you a nice full picture, notes are boring… having read both the cfai books and schweser for l2, i did not find any topics that must be read from cfai books, schweser does a good job, but i find that the confidence and strong base you get from reading cfai books once is worth it

Ideally, all of them. Reading the material in two different ways probably helps retention. In a world like ours with limited time, none. Maybe the occasional exceptionally complex reading, or one where you got a bad vibe after doing the EOCs right from reading Schweser.