I recently put on a new set of the Oregon gator blades on my 721d 61" and I have to say that they have the best cut out of all the blades, and it feels like the mower is even running stronger. The one down side is that it also makes the most dust and grass is blowing out of the front of the deck, especially on the front left side of the deck (non discharge side). I don't if anyone has experienced this or has any suggestions to minimize this. Either way I'm sticking with the gator blades!! I have the older style deck SL61