Get the brakes!!! First, over the time of use the addition of surge brakes in the initial cost is really not much.
I once had a dolly without brakes. I was towing down a steep mountain grade from apple country back down to the freeway. Half way down it began smelling my brakes, then they became soft under-foot. I safely pulled over, told the family that it was time for lunch and this looked like a good place. We had a picnic, let the kids play, and killed about 2 hours. I felt the lugs were now cool to the touch, so I preceded slowly the rest of the way down, in 2nd and 3rd gear. Before the next trip I traded the dolly in for a Demco KarKatty II with surge brakes, and used it well for over 25 years. 
Happy Trails