How many sharpenings or hours do you usually get out of a set of blades but you ditch them? I have been through three sets of blades with about 245 hours on my machine. Another note: I put on a new set of Toro High Lift Blades yesterday. WHAT A DIFFERENCE! I have been using the stock medium lift blades. The new high lift blades left a much better cut and cut clippings better as well. I will never go back.