Fish- I have a set of the Discoverer S/T on my 2500HD. Love em. I'm probably going to add them to my 100 in a few weeks but I have been checking to see what else is out there. The tread depth is nice and I have had no problems with them. I am in Pgh, PA and drive to Syracuse about 1x per month for business. The Discoverer S/T's have gotten me through some nasty lake effect snow, they ride nice and are not too loud on the highway. I have a boat launch at my camp which is mud and river rock and on a pretty good incline. I have not had any issues yet. I was thinking of going to 285/65/18 on the 100 with the S/T's. I only got my '06 100 on Fri. So I have a lot of work to do on it.