Mark-Very thought provoking question.
My view is that the best work is done through refinement of the classic design. I think there would be concensus that the 1960-1985 era was an extraordinarily fertile generation for design. When you start to really look closely at many of the watches (thanks Arno for the magnificent photography), it is hard to imagine that that you can improve on them. When you look at the visiblle components--dials, cases, hands--they are all pretty simple, and once the automatics started, the formal logic and clarity demanded by race timing created a pretty consistent design vocabulary. Arno's photos also help see the beauty of the case designs and grinding patterns.
I think Breitling did a nice job with the Chronomatic reissue. It may seem really petty, but there is something really unappealing about the TAG logo--the pure Heuer pentagon is so clean and iconic. The new one looks cluttered and contrived, so in my view, any reissue with the TAG logo gets 5 demerits from the start. If the Monaco reissue had correct pushers, it would be right. There are a lot of manufacturers--Bremont, Tenmption, Sinn, who seem to be reinterpreting historic chronograph desgin with more excitement than Heuer.