This topic hasnt been dealt with very much in this homeowner assistance forum, but the commercial guys seem to have discussed it a lot. I went browsing there looking for opinions regarding how frequently one should replace mower blades, because the operators manual for my Exmark doesnt really address that point other than that they should be inspected and sharpened or replaced as required. It sounds like those who mow lawns for a living keep a lot of sharpened spares on hand and they remove and replace them frequently........every 4-to-10 hours for some. I had been doing it only once every 30 hours. But Im a homeowner, so maybe thats typical for us. I couldnt find any post that addressed what other homeowners do, so I thought Id ask. May I have some feedback? And while youre at it, for those who own some other manufacturers mower, please let me know if it has a recommended interval for blade sharpening and if there is any criteria for when the blade should be replaced rather than just sharpened. A related topic is what about the raptor, gator, etc. blades? I realize they are for mulching, but I had never given it any consideration. Sooner or later, however, Im going to be buying some new blades, so I wonder if its worth spending the extra bucks for these. And if so, which one? Any opinions?