Yeah, rotational mass is like 4x as bad as static mass or something - that's why you should lighten wheels moreso than frame.. also cranks, pedals and shoes as they rotate as well. But, as you will notice with tour riders, weight isn't eveything. Depend on your speed it's often better to use slightly heavier rims that are more aero than less aero lighter-weight rims.
Yeah, rotational mass is like 4x as bad as static mass or something - that's why you should lighten wheels moreso than frame.. also cranks, pedals and shoes as they rotate as well. But, as you will notice with tour riders, weight isn't eveything. Depend on your speed it's often better to use slightly heavier rims that are more aero than less aero lighter-weight rims.