I own an ECHO Bear Cat 75311 (SC3342) Chipper/Shredder. (A great machine.) I have owned it for five years. This is a great working & beautifully designed piece of machinery. I change the shredder knives ever couple of years because I shred a lot of leaves for composting every year.
I usually process about 10 - 12 yards of chopped leaves each fall. The 75311 (SC3342) Chipper/Shredder chops them up just great. After rotting down, I end up with 5 - 6 yards of great soil for the garden. All made possible by my ECHO Bear Cat chipper/shredder. Couldn't be without it. It really is one great machine.