It's no better than Maple. Rational Functions in CAD Computer Aided Design uses rational parametric curves a lot. They have several advantages. A circle can be exactly represented by a quadratic rational parametric curve, but not by a polynomial parametric curve of any degree. Perspective transformations preserve rationals, but not polynomials.
Homogeneous coordinates mesh nicely with rationals.
In homogeneous coordinates, the weight coordinate is useful for weighting the various control points differently. However, the rational expressions are derived by techniques that do not try to minimax the error. There seems to be no effort to do this. Therefore, rational curves in CAD don't seem to be relevant. GAMS Guide to Available Mathematical Software , from NIST, is a comprehensive index that has some matches to rational .