Matt,
I've had a couple MT/R Kevlar tires that they just couldn't get balanced. Its been a QC issue with Goodyear dating back to pre-Kevlar MT/R days. A friend of mine who formerly owned a Big O tire store here told me to get 4 good MT/R's they'd have to go through a pile of ten or more due to QC/imbalanced construction issues. And my experience with MT/R's has born this out.
Discount Tire just replaced one of my new MT/R Kevlar tires with a brand new tire at no charge as they couldn't, after repeated visits, get the darn thing balanced.
I like the tread design of the MT/R Kevlar but in addition to balancing issues I don't like how easily (relative) the sidewall rubber slices. And the fact the new MSRP for my size is $487 EACH with zero QC and rubber compound improvement puts me in the 'new tire shopper' category.