I have read that the 10 degree is good for an ledengin 10w, but I don't think I've seen anyone test an 8.7 against a 10 for an ledengin 10w but I do know from experience that a 10 degree lens works twice as good as a 5 degree on the ledengin series. don't care what the light meters say, my blades do not light up evenly with the 5 degree. if I had a 10 degree that didn't require a complete uninstall of the soundboard to get to (mkvi) I'd do a test with my 34" ultraedge blade, but I don't.