I have one of the Kitchen Aid ones, and it works pretty well on venison.  I trim as much as possible, and it does clog after a while (easy to fix though, just unscrew it, scrape or use kitchen sink sprayer), but overall it works way better than the hand grinder I had.  When that one got clogged, the end would actually pop off the threads.  Apparently Pro-Cut is good, but that is many, many more bits of green paper.