Hey Mike,
I looked over the DR site, and it doesn't seem like there is any more to steering than manhandling it, like you said. I've never been near one, so can't be sure.
If you're open to other brands and are searching for new, I'd recommend a BCS 853. The 853 has differential lock and steering brakes. When going along a hill, you'll appreciate the fact that you can unlock the differential and ride the uphill brake to keep it on track. Four forward gears. You can get it with a 13 HP Honda or 11 HP Lombardini diesel. You'll never need more power than that. The rough-cut mowers come in 21, 26, 28 and 31 inch It has many more options for attachments than the DR, including a tiller, rotary plow, snow blower, sickle mower, finish mower even a round baler.
The biggest disadvantage to BCS are the fact that the engine hangs out the back of the wheels, limiting how deep of a ditch you can go through. You can buy taller wheels to overcome this, but it's aggravating when it happens. This is not really an issue with any attachment other than the mower in very rough terrain.
Earthtoolsbcs.com is a very comprehensive site to see all the options. Used versions include the 735, 605, 830, 850, and 852.