http://www.bikefitting.com/English/Frame.aspx
Here is an interesting article on the comfort parts of bike fit that indicates saddle angle is an important part of the weight on hands feel. ie: a saddle tilted forward leads to riders sliding forward and thus having to support much of their weight on the hands.
This whole series of articles is very interesting and if you back out to the basic bikefitting.com you can follow several paths through different aspects of bicycle fitting.