I just used U-haul twice to rent a tow vehicle and it went great. Although I had read in various places that you couldn't rent a tow vehicle, I called uhaul in Kingston (near the P.O.) to get what I expected was the official rejection. To the contrary, they were fine with it. I was open about my use and they were helpful and great!
I rented a Ford F-150 at $29 +.59 per mile to get my new-old 65 Safari from the previous owner's yard on the side of a mountain near Woodstock to the Camper's Barn RV shop. The only wrinkle was the pickup had just a four wire connection for the umbilical so there wasn't going to be a brake controller. Since the pickup was rated for twice the weight of the Safari I felt comfortable going ahead for the short 20 mile tow. It went off without a hitch (pun intended).
After getting new tires and bearings at Camper's Barn (nice folks there, but expensive), I discovered having someone else haul the Safari 200 miles to Shelter Island was going to be too expensive.
Since U-haul doesn't rent their pickups for one-way rentals I rented a 10 foot U-haul van and felt the extra bulk would add to the safety of the trip, anyway. After discovering a problem with the truck's umbillical connection for the lights, U-haul switched me to a 14 foot truck. I had no worries now.
I towed 200 miles, from Upstate New York, through Westchester and over the Tappan Zee bridge, across the Bronx and over the Throgs Neck Bridge (where do they get these bridge names?). Then down the Long Island Expressway, through the Hamptons and across the South Ferry onto Shelter Island. It was a great trip. I was a nervous tower to be sure, and having my wife following in our car both keeping and eye on the Airstream and blocking traffic for my lane changes made it much easier, but it really went swimmingly.
The only headache really was the lack of sway bars or stabilizers. There were a couple of times I got some wiggle going, but nothing awful. It was probably just scary to me as a first-time tower. I definitely had a better handle on that by the end of the trip.
The U-haul details are that the trucks are equipped with a 2" ball. The pickup actually had a removable ball hitch that they issued to me at the time of rental. They keep it in the office so no one walks off with it. They even gave me my choice of balls so I could get the right drop to give me the correct hitch height. The 10 foot and 14 foot trucks had balls that were permanent, but the 14 footer had an extension past the ball that looked to me like you could use a different ball. The 10 footer might have had the same arrangement but I'm not sure.
While the pickup was only equipped for a flat four-wire lighting connection, the larger trucks each came equipped for both four wire flat and 7 blade round. I don't know if the larger trucks had a break controller because I wasn't equipped to use my 7 blade round.
U-haul was great and I would recommend this to others in a heartbeat!