I have not tried this modification, but I think that:
> Tall 0 0.5 0.01
may be even more sane than what you changed it to (Tall 0 0.01 0.5)
considering that Tall is documented as such:
> data Tall a
> = Tall {tallNMaster :: !Int,
> tallRatio :: !Rational,
> tallRatioIncrement :: !Rational}
What do you think?
Adam