mixed results. i have the same mower as you...not sure if you have the 15hp or 17hp??
I have the 15. i think the stock blades work best. i have used wavy exmarks and didnt notice a difference. Trick is to put the blades as high as they will go with the spacers. Keep em sharp. Im using the plate with stock blades now and its actually working pretty good. I will put my kit on around octoberish and leave it on until may. It is just a PITA to remove if I have to and i get mixed results with it. Fall/winter? works great, especially with leaves. just keep those blades sharp! im sure the higher hp motor will work better too, i just dont have that.