Often you'll see comments about how SR is most effective when you create your own cards and that using off-the-shelf cards isn't effective. But what I've found is that the biggest barrier to using it is the card creation itself. If I have cards in a system, whether it's Anki or otherwise, I am pretty consistent and find that I recall the information in my notes far easier.

I think there's a credibility/trust issue, though, with taking other people's card decks and using them, assuming the info is accurate.