The number one problem with note taking for me is keeping track of all the notes. In the past, I'd make all these great notes with Zim then never read them. With anki and spaced repetition, that problem is solved. When the memory of the note is on the verge of decaying, anki reminds me, keeping it fresh.

Anki has a web, android, Windows, Mac, Linux, and iOS client, it features online syncing, supports html markup and has extensions support with python. Works for me!