I got nearly 145k on my OE brakes on a NBS Tahoe and replaced only due to a warped rotor...My buddy swears it was because I never used the brakes which may or may not be partially true! Sounds like you have the same problem!!!
I tow a lot, and this is the set I will buy when my pads wear out... which doesn't look to be anytime soon. I'm at 128K on what I believe are the originals so far.