It works great in the fall on leaves. I took it off in the summer because it can pull the motor down if you let your grass get away from you a little. I will say I'm not sad I bought it. It's pretty easy to put on and take off. The blades don't have as much lift so I had low spots that didn't mow very well. My backyard has a valley with extra water while other parts are dry. So in the summer I slow down mowing and the wetter spots keep growing. That causes me issues. When you mow really heavy, thick, and tall grass it leaves unprocessed grass on the discharge side. So I take it off and just use my lawn sweep on the heavy spots. If you keep ahead of the growth I bet you'll like it.
I made my own mulching kit for my 1026R last fall to mulch leaves, when they were falling very slowly. I have used mulching push mowers to mulch grass before getting a tractor type mower. I was never real happy with the results of the mulching push mower on grass, so I never considered mulching grass with the tractor mower.