Puppy, you mentioned the integrated brakes. While in theory its a great thing but unfortunately, they fail and need constant adjustment. They were once replaced on mine (the entire drum on both sided) and the mechanic failed to tighten one side down and it caused the keyway to chip out the axle. I was blamed for that but luckily for me, since I'd gotten to know the warranty guy here so well from trying to fix the deck, he ok'ed the free replacement of the wheel motor.
Good result in the end although it never did run straight after that but that was all caused by your fantastically designed park brake!
You see, with the weight of the machine being towed around on a trailer, any movement wears out the brakes. Even strapping the machine down wasnt enough, they always needed adjustment after a couple of weeks or months. If they needed adjustment they were getting worn and would need replacement.
Since I assume you rarely put your machine on a trailer its something you may not ever have a problem with!
After you had your brake problem I checked with a couple of dealers along with Hustler, both dealers along with one of their head mechanics had not seen enough brake problems to honestly remember. Hustler was aware of the problem as you explained but said the incident rate was virtually nonexistent based on warranty claims. Hustler of course made the statement there would need to be considerable movement in repeated fashion before brake damage could occur.
I have spoken with several commercial cutters that trailer numerous Hustler Super Z mowers daily, and other than adjusting the brakes they've had zero problems.
I just got off the phone with a commercial cutter I know that has owned and operated Hustler Super Z mowers for years, kept 5 to 7 mowers averaging around 800 hrs. per mower each season mowing nothing but large commercial properties. He has trailered his mowers thousands of miles and never once had a brake failure on the integrated brake system. What this is saying is he has trailered his Super Z mowers and cut more hours per year than probably several people lumped together posting in this forum. How many people would you need to put together to mow 4500+ hrs. per year, people that mow that number of hours have no time to post on LawnSite, he had just walked in from cutting his own grass when I spoke with him.
I also asked him if he ever had clumping problems with his 60" VX4 decks, of which he said, "I've never had cut problems, if so I would never have owned as many as I have." This is nothing more than the difference in areas being cut, and I've seen his hired help cutting in wet, raining conditions.
I also found this interesting, at the beginning of this cutting season he bought 7 Bobcat Predator-Pros and ProCat mowers. I asked him why the change after so many years with Hustler, he said, "sometimes after so long a man just wants to change colors, and they made me a deal I could not turn down. I saved $28,000 and the Bobcats are doing the same job the Hustlers were and I can actually slow my help down, they want to mow at whatever speed the mower will run and these mowers are fast enough to be productive but not excessively fast like the Super Zs."
Don't concern yourself about getting involved, you are doing no more than giving your opinion based on your experience, whereas I am giving my opinion based on my experience and information gathered from many different sources of experience.