As far as I know, GaGa ABS only cover the front wheels, shouldn't affect. As for the rear disc brake installation, need to cut & paste with welding.  Reliability wise... No comment.

Decarbonize most said it works. I personally think its some sort of gimmicks to make u see smoke blowing out of exhaust pipe, that gave u placebo effect. Engine so new, I doubt there'll be much carbon inside anyways. Provided fuel injection system nowadays is extremely efficient. Take it with a pinch of salt. My going to be 5 years old BLM still working at its optimal condition, proven on dyno machine. Hence there's no need for me to consider decarb at all.

Here's a calculator: http://www.tyresizecalculator.com/tyre-whe...rror-calculator

a lot of ps3 user feedback sidewall too soft, and very quiet... so it seems weird looking at your feedback