Troybilt, Yard Machine, it doesn't matter, they're the same machine, both produced by MTD, the Walmart of the yard equipment world. Do a Google for both MTD and it's related products and consumer satisfaction. You won't find much praise. Don't despair, there are good machines out there, they cost a bit more, but they're good machines. The easiest way to save money is to buy second hand. I picked up a MacKissic 9P (now know as a 12P ) in excellent condition last fall for $200. It's a 30+ year old machine that's still supported today - you can't say that about MTD equipment or the brands that they've acquired (i.e. Troybilt, Murray, etc. ). I found mine on Craigslist.
Now, before getting into what brand is best, the question is, what are you going to be running through it so as to suit the type of chipper to your needs. I too have several mighty oaks that drop a plethora of leaves, unfortunately, those leaves are mixed with acorns, sticks, and twigs and anything else that falls from the trees, as well as gravel from the driveway those leaves fall on. The manure source I have for the garden and compost also contains rock and debris. All this to bring me to my point, I needed a chipper that could withstand extremely hard objects run through it without damaging the implement. There are two types of chipper/shredder, one that has knives on a drum and one that utilizes "hammers". Obviously, knives would not look kindly to having rock fed to them, so I opted for a hammermill style. I was able to reduce a pile of leaves from 15' diameter and 3' deep, to a pile a mere 6' in diameter and a little over 2' deep. That's a substantial reduction in mass and the material composts much faster and easier, there were also no discernible rocks, acorns, or twigs of any kind. With the right screen, a hammermill style chipper/shredder won't plug up like a knife chipper, and it's easier to clear when it does. IMHO, your needs are better suited to a hammermill style as well. You'll surely have plenty of sticks and twigs running through it that the knife style chippers don't really like - particularly the hard dried ones that fall from an oak tree.
Check out this link to see the MacKissic machines, they carry both styles of chipper/shredder. http://www.westpowertools.com/mackis...ipper-sc7.html As previously mentioned, there are other excellent brands as well. My only recommendation is that you stay away from anything manufactured by MTD.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!