The one that was totaled was also an '02 but that's all I've run. I don't know the details of the issues but I know the VT365 (aka 6.0L) has issues. Mine have been great for me, just normal maintenance repairs.
I don't remember the weight of the trucks. I want to say the 4300 is about 16,500lbs. I would guess the 4700 is around 13,000lbs. Normally, we put 5 ton in them and go down the road. If we need more we order it or make a couple trips.
Anybody using a lead tracking software, such as http://www.zoho.com