Ooohh, jealous. I have so many limbs to chip at any given time, I need to look more into one of those...
I unloaded and assembled the wood chipper, adjusted a bunch of stuff, and made two boxes of chips for the retirement center gardens (not all are pictured; fortunately I had help making and distributing chips).
The U.S.A. Made MX8600 is indeed a monster in need of feeding. I've operated an industrial 25HP gasoline 8" chipper and the WoodMaxx 6" keeps up with it (maybe due to new blades in the WoodMaxx). with no noticeable blade wear. On the industrial chipper when the cutter RPM slowed down it would stop the infeed and wait for the RPM to raise, then feed. The MX8600 will automatically "throttle down" the infeed if adjusted to do so, meaning there's no recovery time it just keeps feeding, although chip size won't be uniform (if that's important). I was pretty hard on it and didn't break any shear pins (bolts) nor anything else. The MX8600 MX9900 have staggered inner and outer knives so it
easily manages multiples of smaller branches without issue--WoodMaxx did not overrate this machine--they say 15 PTO-HP minimum, I have 17.5 and it runs great with hardwood, softwood, any wood.
The only things that could use improvement are 1.) the discharge shoot--it doesn't aim high enough for shooting into a box on a trailer, or low enough to shoot into the same box on the ground (I'll likely fabricate a different shoot end for it), and 2.) rubber feet are not included by default, so setting the chipper on concrete after forgetting to adjust the 3-point drop rate can be a bit cringe.
OH! I also found the water drain hole at the bottom of the flywheel housing can get plugged up and not drain, so if you hose off the chipper to keep it and the storage area clean check underneath to make sure it's not holding water; after seeing water when checking the blades I poked a small screwdriver in the drain hole and all was good.
U.S.A. vs China made: For the difference in price, U.S.A. hands down. Far lighter and more capable, plus it's way easier to inspect and service the blades (which is extremely important in order to have a well-running chipper). The increased U.S. quality is a dramatic improvement, spend the money.
Power Feed: Well worth the investment. If you're buying a chipper it's because you have more than a few weekends of work to do, and one this big isn't something you want to hand feed--not only because it's a lot of work but for your own safety--you do
not want to get hit in the face by a tree branch that twists and moves while being chipped.
Disclaimer: Realize I'm not trying to compare a WoodMaxx PTO powered chipper on a 23 HP tractor to a $62,000 42 HP Vermeer chipper, I'm saying for a 6" chipper this is a great unit at a great price.