I've had mine about a year or a little longer. It was the second model that had the cooling fan added.
One way to add life to your shredder is to derib and shred in one operation. It is just as fast or faster than deribbing and shredding in two operations. Most guys do all their deribbing first and then feed the machine as hard and fast as they can go, with very little break for the machine until they're done shredding everything they've deribbed. This works the machine pretty hard, especially if you're feeding alot of leaf fast.
I sit at the shredder with a bag of whole leaf in my lap and a trash can next to me. I derib a leaf and feed it into the machine. While it's shredding, I am deribbing the next leaf. The first leaf usually finishes before I can derib the next leaf and the machine shuts off. Then I feed the next leaf. I'm feeding one leaf at a time, but since I'm deribbing at the same time, I'm shredding in about the same amount of time that it takes most people to derib only.This way the machine is lightly used and gets a short break between leaves. I truly believe that this has to add life to the machine and is just as fast.