I use a 3 foot bush hog behind my B6000E and don't have a reverser. The only thing I would see a reverser would be good for is a tiller or a post hole digger. The bush hog doesn't care which way the blades swing, they go whatever way the pto tells them to. Just sharpen whatever side of the blades you need. I use mine quite often.
If a reverser didn't cost as much as I have into the tractor and bush hog then I might think about it but with the cost involved I'm perfectly fine without one LOL.