2 blade = more power
3 blade = more speed
At least that's what I experienced with my old 67lb TM. The 3 blade was real jerky if speed control over #3. On speed 1 or 2 not much difference.
From Genesis: "And God promised men that good and obedient wives would be found in all corners of the earth."
Then He made the earth round...and He laughed and laughed and laughed!