I got into SRS because my brother used it to get 95 percentile in the board exam - he was only an average medical student before. Then, I used SRS to get to top 1% in the national biology exam. At the same time, I used SRS to cram for N3 in 2 months (1200 vocab + 1/3 of Kanzen Master Level 2 Grammar) and got 144/180, and soon I got a 5 on Japanese AP while all my classmates did abysmally. I will continue to use SRS and smoke 90% of the people in university.
SRS requires 2 things 1. put in work to create cards (eliminated if you use core2k, but required for stuff like biology, etc, because you need to understand what you put in the cards). 2. consistently review everyday - this is best done during commuting.
Many people give up on #1 because they think it's too much work - while actually, it's NOT because you can read the textbook once and never have to go back to it again. This is much more efficient than reading the thick and sleep-inducing textbook multiple times.
The few that start #2 don't make it a habit and kinda lazy off - so they don't see the results.
A victory for the forces of good: a good friend is studying Italian, and has asked me repeatedly about my use of Anki. She's now using Anki in conjunction with Pimsleur and (currently) LiveMocha to boost her vocab.