> I would almost argue that reading for information (as opposed to aesthetic enjoyment) is a hugely inefficient waste of time if you don't use a SRS system to retain what you've learned. I've probably read hundreds or thousands of books in my lifetime, but I can really only remember the minute details of the ones I've added to Anki.
I use Anki (and the classic version of "SuperMemo") a lot, too. However, I mostly use it for learning languages (vocabulary), or for more complex material in case a test/exam is coming up (to avoid "cramming").
However, I see two problems with such SRS systems, now that I've been using them for over 10 years:
1) I can often not recall the knowledge in real life, simply because I study _both_ the question and answer side of the card - in other words, if I'm asked the question in a rather different way, I might not recall that I know that fact at all. The most extreme example of this was that certain flashcards broke after a while, e.g. showing a gray (instead of a white) background in the question card, for some reason. Whenever that gray card comes up I know the answer immediately, without even having fully read the question (which I forget over time). So in the end, what my brain remembers is:
<question card with a medium-length sentence and gray background> comes up -> answer = "propensity". (I'm learning English as a foreign language).
2) A lot of knowledge in books that I read (let's take the "Pragmatic programmer" as an example) is not suited for flash card system learning. It's knowledge of the form "if this happens, do that", e.g. "if you are about to write a new method in your source code, think of how you would test that method first, to improve the method's quality". Sure, I could create a flash card that has the question: "what should you do when you write a new method?", but it's pointless. These kinds of things require deliberate practice for the specific situations, when you are in the IDE, not in the SRS software. It's methodological knowledge where, in the end, it doesn't matter if you could answer the question when someone asked you about it on the street, but it matters that you remember when you're in the actual situation.