I had some windrows of leaves all ready to mulch with my LB 10201, but it didn't want to start today. So I got out the LB 10684. The reason I didn't try the LB 10550 is, I tried it before, and debris gets jammed in the wheel gears, requiring a stop to remove the wheels and clean them. The 10684 has a better shield on the inside of the drive wheels, so I gave it a try. Wow! Now I have a new leaf mulcher. I don't like to mulch them on the grass, but I had to this time, coming back with the 10550 to bag up the debris. The 10684 never had the slightest problem with debris in the gears, and it has tons more power than the 10201 anyway. You know what this means - that was the only reason the 10201 was kept - to mulch leaves. I might just take it for 'a little ride'.