We have a Knight 5055. I have been able to mix up to about 9000lbs in it depending on what the feed material you are using is. We typically grind a couple of big round or big square bales and then put in some silage and corn. The mixing time really depends on how hard the bales are, a general rule of thumb would probably be 20 to 30 minutes to get it loaded and another five or 10 to get it thoroughly mixed. This wagon has a gear box on the bottom that drives two enormous bull gears that spin the two augers. It has required very little maintenance over the last ten years that we have had it. Occasionally we have to replace knives and weld on new material lifters on the leading edge of the augers. I have also replaced the chain on the conveyor once.