Nickschaos81, I'm going through the same stuff right now with my new G2s Geeetech printer. I'm bringing up the Marlin RC2 (Release Candidate 2) on it. There are some extra adjustments available in the newer Marlin's. You get to trim the endstop adjustments for each tower and you get to trim the diagonal rod length for each tower.

I'm pretty level right now, but I need to figure out how to use the diagonal rod trim to fix one place I have the nozzle lifting up too much.