I guess killing the AFM on engines that have it is a big deal. My 2010 Silverado LTZ-Z71 has it and I've experienced no problem with excessive oil loss or any kind of acceleration lag.
Most tunes, like the popular Black Bear Performance will eliminate the AFM, if not wanted.
http://www.blackbearperformance.com/Personally, my 2010's mileage and performance is so darned good that I've not investigated trying to improve a vehicle that has been perfect in ever way.
kd
