SRS advice

I have made some significant progress in organizing myself with org-mode (basically a really well thought out emacs outliner) - consider this a plug :).

Now I think I am ready to bite the bullet and automate another part of my mental apparatus, memorization. I’d like to hear other people’s experiences with SRS—spaced repetition - (negative, too), what software they use, what do they use it for, how much time they spend. I expect these to vary, so stating your reasons is worth an extra upvote (and thanks ahead)

ETA: When do you decide something is worth memorizing vs. putting it into a searchable database?