Last year was my first year using SBG in my algebra classroom. While I still am working on being efficient, the time it took was well worth being able make the focus on learning over just results. With SBG the feedback is helpful and drives learning rather. With the traditional system, my students used to just stare at the grade.
Check out my overview here: http://musingmrsg.blogspot.com/2015/03/standards-based-grading-presentation.html
And how I turn SBG into a traditional letter grade here: http://musingmrsg.blogspot.com/2015/04/standards-based-grading-meets.html