cjc -
Sorry to hear about your troubles. One problem with conversions is that they are custom, and with every one built there are probably new issues that pop up. I think any info you can provide about issues is going to help others when they configure their rig. Overhang, wheel base, tandem or single axle and tongue weights are all huge items to consider in your conversion design.
How long is the overhang? I would think 12' would be max, but I am sure there are longer. On my first unit I had a 10' overhang, which never dragged. The problem for me was the 28' wheel base which made my turning radius quite huge. That setup was awesome on the highway, miserable in tight places. The new one has a 11' overhang and so far no dragging issues. Should Show Hauler swayed me from building with that long of a wheel base? I know they sway people from going any longer, but as far as telling you all of the issues that come along with a certain setup, I am sure they feel that is the owners responsibility.
I am not a good person as far as telling people about problems with his Show Hauler. My 02 was flawless as far as issues. A couple of very minor things popped up, but where all little things that I easily fixed myself. I am on my first trip in my new Show Hauler right now and as soon as I get back next week I will post my thoughts, experiences and issues. Just a few issues; my Norcold fridge has a blown pc board so it will only run on propane, and a small leak in the shower which was easily fixed with some silicon caulk. I have a few minor design issues which I will expound on next week, but they are very minor.