I was thinking of testing these blades out on some of my machines. How do they last? Do they sharpen like standard blades? I need a little more info before making a purchase. Just considering them after reading thread on what we'd like to see from new blades. I'd have to agree w/ Gamba - no clumping & no double cutting. Very tough to avoid w/ cooler season grasses in these areas, especially in spring and wet seasons like this year.