mustache instead of ejs

I'm coming from a backbone/underscore development experience and for my next project I was thinking to try something new. I'm interested in using canjs and ejs as the template engine. I immediately liked ejs since, as underscore, uses all javascript logics but I noticed you switched to mustache as default template engine. Isn't mustache much slower than ejs in terms of performances? Is there a reason why ejs has been dropped off?

thanks