Mine started at around 8K miles. @kylant are you having the pads replaced under warranty?
@nutdriver, my goal would be to beef the brakes up, stopping 8,400lbs is a tough job. I follow a guy who put the EBC Yellowstuff pads on his powerwagon and they are pretty sticky based on his review (I validated this also). I always try and over do things on my trucks though. Just part of what makes it fun to me.