I have had several friends that owned them as race car haulers. Every one loved them. I almost bought one when I was still racing and had a friend loan me his for the weekend. We went to a racetrack about 700 miles away and it was pure heaven towing my 40' featherlite gooseneck with it. Fully loaded, with the race car, tools, etc, the trailer was right around 12,000 lbs. His Freightliner had the 450hp engine, and if memory serves we got like 7-8mpg with Lots of hills. My normal tow rig was a 2001 Ford dually with the 7.3 and the Freightliner made the trip way less stressful, absolutely handles like a dream. Granted, my old 7.3 dually was not up to par with the new offerings, but it was like night and day towing with this rig. Had I not gotten out of racing I surely would have owned one. The low mileage example in the link is a little pricey but I've come across several of them at pretty attractive prices.