I struggled all last season with my XT brakes. I tried toe-in, toe-out, no-toe, big-toe, broken-toe, fat-toe, etc. I spoke to several wrenches at bike shops. ALL just shook their head as if to say, "too bad for you." I asked the guys at the Shimano tent at the Mt. Snow NORBA last August. "Try new pads." I tried Kool-Stop, and new Shimanos. No luck.
I gave up.
Bought Avid SD7s and can say that there is no loss of stopping power, they are quiet and 100g lighter.