From what I have heard from talking to the ones that use the Choppers, they work out good. They are hanging weights on a bolt on bracket they make on the back and they are getting good traction with the Boss 2 tires.
If you have the diesel model, you can even have hydraulic lift that will run off of one hydro pump, or if you have the gas model, you can get electric lift. Which model do you have? I have one of each and I am thinking about using the diesel instead of my JD 430 that I have used for the past 10 years. If I do this, I will build a cab like I built for my JD 430 pictured on my website.
I have the 20hp with a 60" cut. I won't buy one until late fall, but since I just got the mower, I thought about it when choosing what brand to buy.
I wonder if I couldn't adapt another blade to use though, such as I might find at the local used farm equipment sales. It probably would be cheap and easily adaptable since from what I can remember, the DC blade just bolts to the front bumper. A little engineering could go a long way with say, a 54" blade.