Reading this long SRW versus DRW pickup thread has really been a hoot!
I'm an E450 (1 1/2 ton) DRW truck chassis 24 foot Class C owner. Most smaller Class C rigs are on the E350 (1 ton) DRW chassis, so my E450 chassis was an over-kill option for our short Class C with it's total weight of only about 11,800 lbs.. The duallies of the E450 are even 4.5 inches wider that those of the E350. I suspect that most one-ton dually pickups have a dually width of about only that of the Ford E350 cutaway van dually chassis - NOT the 4.5 inch wider width of the E450 cutaway van dually chassis.
What this means is that I have really learned to deal with "wideness" when driving our Class C - it's box at 101.5 inches is even wider than the rear duals' stance. It took me a couple of years to "get used to it", but now it's a piece of cake.
We park in two spots in shopping centers due to it's width to keep dings to a minimum, even though at 101.5 inches box width it still fits just inside the lines in a regular parking spot. We do drive through downtown San Francisco with it. We have taken it into downtown Cincinnati, too. It's ultra-stable on curves, canted roads, and in high side-winds due to it's rear dually width. We take if offroad in the desert, including rocky roads -> we just slow WAY DOWN when we do it. We carry pruning equipment along to prevent getting scratches on the sides or top. We even crawled along for 50 miles in the Oregon Outback once with no problems. One time we had an outside dual flat on the highway, then drove it about 5 miles very slowly on the inside tire. Even though the good Michelin tire was way overloaded doing this - it worked and got us to a tire repair shop. The temporarily overloaded tire went on to serve us many years after that.
I love the solid handling, secure feeling and "backup spare" that the duallies provide. I've never experienced it, but I suspect that the rock-in-between-the-duals may be an overblown concern. We've never experienced it ... however our rear dually wheel wells are steel lined anyway to prevent flying rock and shredding tire damage.
Even though our E450 cutaway van chassis has only 16 inch stock rims it's rear dual tires can be up to 235/85R16 in size (mine aren't that size), and in this size a Load Range E 235/85R16 tire is rated to carry up to 2778 lbs. each (at 80 PSI) when used in dual configuration. Hence, four of these at 80 PSI in the rear of a 1 ton dually pickup can handle 11,112 lbs. in just the rear alone. If dually pickups come normally stock with only 16 inch rims, I can't image any TC situation where four 235/85R16 tires at 80 PSI wouldn't be up to easily hauling the weight.
I wouldn't be afraid at all of going the dually route in a pickup. By the way, does a dually 1 ton pickup HAVE TO be a crew cab? Can't they be ordered with only an extended cab - or even a standard cab if desired, for use with a camper where you want the total length and turning radius to be smaller?
FWIW, our rear differential gearing is 4:58, so the V10 pulls up any highway grade at full speed at all altitudes (I've only had it to around 9500 feet) just fine as well as crawling along offroad at 5 MPH if needed. We turn about 2000-2100 RPM on the highway in OD in regular or TOW/HAUL tranny mode. At our total weight of 11,800 lbs., diesel is not needed. We go many places where diesel isn't readily available anyway, so gas provides more flexibility.
