i love my mtrs, besides whats already been stated, i dont really have much else to say. never heard of a tire causing more wander on the road tho. mine dont, atleast not until the front sway bar bushing were destroyed. handling has always been great for me. i have 40,000 on mine now and expect about anouth 10 to 15, the tread on all of them is 9/32nds as of right now. i rotate my tires every oil change tho and have also flipped them from white wall to black halfway thru their life span to even out the cone-ing casued by running wider tires and turning.

if you are doing 15-20,000 per yr (so do i) i woulndt recomm buying mtr's unless your prepared to buy new tires every 2 1/2 years. i have often contemplated running 2 sets of tires, one for wheelin and 1 for street.
im halfway thru buying my second set right now. they are not cheap.