My understanding (somebody correct me if I'm wrong) is that the Ninja is the better mulcher for grass. The Ninja does not produce much lift, so mulching grass is no problem. Introduce something heavier, like leaves, and the Ninja might not produce enough lift to mulch it as well.

The Gator produces greater lift, so it should be more effective at mulching leaves while still doing a great job mulching grass.

The Ninja produces extremely fine grass clippings. I found that after mowing with the Ninja, clods of clippings would occasionaly build up under the deck and fall out as I pushed the mower up the driveway back into the garage. So far this has not happened with the Gator.

Try the Gator and let us know what you think.

I tried the ninja blade on a hivac bagging snapper walk behind. It mulched ok, but the cut was not that good; too many lone standing blades of grass, and little ridges along too many of the cutting rows. Bought a gator blade, cut half of the front yard with the ninja, and then changed blades and cut the other half with the gator. Gator clearly did a better cut and mulching was about the same. Also, there was a LOT of grass build up under the cutting deck. Hosed that out and cut the rest of the yard. Another check showed no under deck build at all with the gator blade on. Ninja has been retired.