It should be noted that Ebisu currently has a severe flaw that causes it to massively underestimate how well you know a card[1]. The author has been working on a rewrite to fix the issue for a year and a half, and is currently asking for comments on the new API for Ebisu v3 which should fix this issue[2]. (The author argues this never would've caused to you to get suboptimal reviews if you use it in the "just give me a few reviews now" mode, but I'm not personally convinced.)

All of that being said, I am a fan of the Bayesian approach Ebisu uses (and Ebisu v3 would allow you to eliminate the awful way SM2/Anki deal with ease factors). Thankfully the v3 Anki scheduler will be pluggable so you'll be able to use Ebisu v3 with Anki on every Anki platform. :D

[1]: https://github.com/fasiha/ebisu/issues/43 [2]: https://github.com/fasiha/ebisu/issues/58