I'll throw in my $.02 as well....
When I moved to this property 4 years ago, I bought an 8hp
chipper/shredder. I don't recall the brand name, but it was a rental unit at a local tool rental and is pretty heavy duty. I needed/wanted something bigger though and after I bought my Deere 3520, I decided to get a PTO unit. I read all the reviews and decided to go with a non-Chinese unit although one of the Chinese units is often mentioned on here and gets rave reviews. Anyway, I started shopping both locally and using SearchTempest.com to scour Craigslist on a national basis. I found a few contenders and ended up with a Bearcat 73554
Chipper/Shredder that I found in WI (I'm in OH). Got it here, used it, LOVE IT!!
It's great to trim up brush around the edge of the yard and just chip it up so it's gone. I've run 4-5 inch stuff through it and it takes care of it with no problem. It's a manual feed unit, but once you've man-handled the material up into the feed chute, it pretty much feeds itself. The shredder takes care of all of the little stuff - just put it in the chute and it sucks it right in. The only "problem" that I've had is if I have a long (8' and up) piece that's at the high end of the thickness scale (4"-5"), it will start to bog down towards the "end of the grind". My solution is either to cut it up into smaller lengths or feed it and pull it out before it bogs down.
Overall I'm super satisfied with my decision to buy one. But, as oosik points out, these units will work you - at least mine works this old, gray haired fat guy!
This past summer my very in-shape brother in law was visiting and helping me with some stuff around the place. We both were cutting and feeding the
chipper hard for about 1.5 hours. Cleared a lot of brush, but we were both sweatin' like pigs when we were done. My point of this is that, as others have pointed out, feeding a
chipper is not an easy task.
I rented a self-powered, self-feeding, tow behind unit many years ago to take care of some brush at my old house. I would advise that you rent a unit like that to see how much work it is to chip up wood. It might also lean you towards either burning (as many have suggested) or buying a self-feed
Woodmaxx that many on here seem to like.
Before I bought my PTO
chipper, I would pile stuff in my woods, let it settle for several weeks and then attack it with the 30" brush hog on the front of my walk behind gravely. That would take care of a surprising amount of stuff, but crap would fly everywhere doing that! I actually thought about buying a small, 48" brush hog for the back of my tractor and doing the same thing, but ended up with my
chipper.
Hope this helps.