I have a Z725 with about 200hr, just bought it in April. I am on my 5th set of blades! the problem is the blades are wearing in the center of the cutting area at a rapid rate. I have resorted to sharpening them about every 10-15 hrs just to get some extra life out of them. I have been mowing for over 25 years and have never seen this issue. the dealer says that he has had no other issues but the mower is a new line. I had originally thought maybe it is a bad batch of blades but after talking with a friend that has the same mower, he is now having the issue too. I also ordered a set of Oregon blades, they have been a tic better but still have the same wear as the factory blades. Has to be a design problem right? kubota customer service is horrible with no phone numbers to call, only email. anyone have any ideas what I can do from here? or anyone having the same issues? any help would be much appreciated! Thanks, Skeeter