KM2 if you're going offroad much and are near mud. I think the MTZ may be a bit quieter on pavement. As for me, I just got the MTR but I love the KM so I suspect I'd love the KM2.
2014 JKU Rubicon- all white with tan leather
LOD front bumper, AEV rear bumper, TeraFlex tire carrier, Shrockworks sliders, Method Standard wheels, 35" MTR Kevlars, Englewood driveshafts, Synergy 3" Lift, Rancho 9000XLs, Artec truss, Teraflex C-gussets, Grabars, HotHead Liners, MORE dead pedal, Tuffy underseat box, Uniden 520 XL, 10lb CO2 tank...