I prefer to make copies as accurately close as possible to the original bows, not only because I think that the old makers were "old" and not "stupid", but most of all because my experience has led me to face the fact that original bows work well on the instruments of their time.
Old makers built bows suited on their clients' different styles (we have many evidences of this) and I follow this rule too, in other words it's no problem for me to make changes to a model according to the needs of a certain musician. The only limitation I give myself is not to change the spirit of the model I'm working on completely. On the other hand, when asked to make a certain model of which no original specimens are still in existence, I reconstruct it carefully having in mind the largest possible number of iconographic sources and treatises, and trying not to invent oddities.
As I wrote above, original bows (or close copies) work well on instruments of their time (or their close copies) but today many musicians don't have correctly mounted instruments for each period's repertoire, or even simply have modern violins with gut strings. In my opinion this approach to ancient music is not a shame, if explicitly declared. The fact is that a modern violin with gut strings, as many beginners use, requires a heavier bow than a XVIII century mountedviolin; a viola bow can be used successfully and is easy to resell when the musician feels ready to move on to a proper instrument and bow.
Compromises can be done (and I do), we should only declare them.
Playing with modern instruments (and techniques) and saying "with original instruments" is not honest, it's just a low-profile cultural production, not only a shame.