Dan,
I have a satoh with a woods rm42 and on the woods mower it indicates that PTO speed 2 is recommended. I've run mine on PTO speed 1 when the field is high and needs knocked down and I've run it on 3 before. 3 speed make me nervous and I only run it when I'm on my lawn and certain of hitting no objects. But 2 is the norm.
Shawn