I don't know enough about the orange KK smaller tillers to even comment. However, the KKII "yellow" tillers are tougher'n a $2 steak, reliable, and they do every bit as good of a job as the most expensive brands. I know of a couple large scale landscape contractors that have used KKII tillers for years with no issues. Mine has a ton of acres on it. I've worn out one complete set of tines and I'm about 1/3rd of the way through set #2. NO mechanical issues whatsoever. I've exceeded it's "rating" most of thetime I use it. Generally, I have it on the back of a 60hp tractor. On occasion, it's been used on 47hp. I've hit rocks, stumps, buried re-bar, and even SOME dirt. The KKII ISN'T "better" than the rest of the popular brands, but that's my point. It's AS GOOD and you'll find 'em everywhere, and find 'em at a good price (without EXTRA charges for shipping)
I'm NOT a big fan of MOST of the King Kutter product line. Th KKII tillers however, they have their act together on this one.