That is a matter of personal preface. This is what they have on towers about the two.

COMMENTS: Some notes on slide valve and rotary carburetors:
Rotary carbs offer a larger response in the middle of the power
band. This works well for off-road applications when throttle
response must be varied.
Slide Valve carbs provide greater response at the beginning and end
of the power band. This works well for on-road and racing
applications for fast take-offs and high speed.