Most of those that have done the conversions have also replaced the commercial fifth wheel with a more "camper friendly" air-ride hitch. Some have retained the commercial hitch, but added a different pin box (such as "Fifth air-borne") that will absorb the shocks that can cause damage in time. When a heavy 5'th wheel trailer is hitched to a lighter truck, any bouncing, shocks, etc. is transmitted to the rear suspension of the towing vehicle. A class 7 or 8 HDT will not absorb these energies, putting all the strain on the pin box and trailer frame.
Unless you have a logging tractor, you won't have any side to side rocking either, again causing extra stress to be absorbed by the trailer frame. Even uneven terrain in campgrounds will present these stresses, so this should be on your list of things to do if you're planning such a conversion. Some believe that removing the commercial hitch makes them appear "less commercial", but that's personal opinion for the most part. Some states may include this in their considerations for conversions, but that isn't usually a major point. Some commercial hitches must be altered (grease grooves welded up) to prevent damage to the camper pin boxes, while other brands will work without trouble.
I am still using my commercial hitch, but I'm not logging many miles yet, either. As long as it's sitting in my drive or at a local campground 50 weeks out of the year, changing it remains on my "things to do" list for now. If we are able to travel more in a few years, then it will be a requirement.
There has been a lot of discussion about this
here.
Jess