So far this season I have spent 10 minutes maintaining, sharpening and replacing my blades on my Exmark WB. On May Ist I removed the mulching blades and micro mulch kit. I then installed a new set of Exmark Excalibur blades. Today, two months or 405 residential lawns later, I removed the still decent excalibur blades, and replaced them with...you better believe it...excalibur blades! The old blades had a few nicks in them, (I hit a softball...and yes, I think I would have made it to second base...) and I think they are good for another month? Not rounded or not dull! Last season I sharpened blades every other day...this year 6 new blades has me out $60 a priceless trade. Blade grinders...HA! I see no reason to sharpen a blade that maintains its edge.