Implementing SBG School Wide

As the school year has started and my campus has had A LOT of training on SBG practices and procedures it seems like all of the departments are in a rush to implement it now.  As we all are tripping and trying to find out how to exactly implement this in our classrooms I keep wondering if anyone has experienced the same problems on their campuses. 

Did everyone try to implement it at once or was it phased in through departments or levels of teachers?

While the school or district was in transition from the traditional grading system (percentage wise) did all of the PLCs or even departments decide to use the same conversion chart from a scale score to percentage or did different departments or levels have different conversions?

The current hot topic at my school is how do we convert the scale score to a percentage that GradeSpeed can handle.  For my students, and primarily the students I'm intervening with and my DB Geometry class I'm using the table below.

100% = 4.0 = I can do it well enough to make connections that weren't taught.
95% = 3.5 = I can do it well enough to make connections that weren't taught, but I'm not always right about those connections.
90% = 3.0 = I can do everything that was taught without making mistakes.

85% = 2.5 = I can do everything that was taught with a few mistakes.
80% = 2.0 = I can do all of the easy parts, but I can’t do the harder parts.
75% = 1.5 = I can do some of the easier parts, but I make some mistakes.
70% = 1.0 = With help, I can do some of what was taught.


Now that's just the student friendly version that I have posted in my room. In my opinion in those classes the students shouldn't have an opportunity to fail. They always will have receiving help as an option and they will eventually (fingers crossed) be able to get some of the work done.  But that's just my philosophy. 

I'm interested in other peoples experiences and thoughts about this subject especially.  We are having a math department meeting next week to discuss our grading policies.  I hope to hear from people!