Interesting points of view on this subject, as I have shot over both at one time or another, the daisy wheel has been replaced by the two tone ball on my flags.
My reason was, that the movement of multiple daisys pulled my focus away from the other details of flag reading.
Now maybe that is because the strobe effect caused flashbacks to the 60-70 lifestyle, might be why so many folks still us them.
Outside of very strong wind conditions I prefer to gauge the wind from the tails, and let the color of the ball indicate direction.
I have kept my set of daisys incase I should have a need to go back in that direction for wind reading.
Now if you want a set of daisy to be true aid in wind reading, just shoot beside Paul Ross and listen to the pitch of the noise they make as the wind increases, his are not only visual but acoustic also.