Yeah, it CAN be alot of drag on the motor, especially if those blades are the thicker, heavier ones. I try to look for the lighter ones all the time, but they're getting harder to find, it seems. To answer the question about sharpening the slats in the Gators, generally, no. I don't, but I have before. I just filed the sides so they were square, and made the points more jagged. Does this make a significant difference? Beats me!

I like to THINK it may, but who knows...they are only used with leaves, anyway. Many leaves are different, as well.