I have a 21st century constellation. I don't shoot it anymore, just lean more the less readical, more "d" profile these days. I think there are plenty of designs out there that mirror the extreme reflex of some of the 21st Century models.
As far as the grip; the buddy grip was amazing and I have said it many times before, the point that pushed me over the edge and sold me on my lastest bow purchase was the grip. I bought a Cari-Bow featherhorn and found the grip to be most similar to the 21st century grip design with the thumb rest and natural pointing, repeatability that I loved about the Constellation.