I was wondering if anyone has used the Stens Raptor Mulching Blades. I saw them advertized on pg. 86 of the new Pro Magazine. They claim they are 25-50% harder than standard blades because of Marbain material. Sure would be nice to go an extra day without sharpening blades. I did a search on Yahoo of Marbain and found that it is used on Scag brand blades. They also are supposed to weigh less which would make them easier to move and less dangerous if they went out of balance. Also anyone know of an online dealer that sells Stens?