Looking for our last toy hauler, I bought a 5000 lb. capacity Sherline scale. I had little concern for the overall weight but since I have an SRW, I was very concerned with pin weight. The Sherline is not perfect but its fairly close.
The Fuzion and the Vengeance we weighed were really close to the manufacturers specs. They both had generators so I assume that was the biggest difference from what the dry weight claim was versus real weights.
As for the overall weight, I asked opinions about this a few months ago here on the forums. Most agreed you'd have to have a very special dealer to allow you to take a camper to the local scales before you pay any money.