Hi Nicolas,
I think you're right - the best part of the classic Longines chronos is the movements. I've been on the look out for a really nice 30CH (thanks to Ubik for his advice) and I even know that I want the 7413 model from the late 1960's. For me a Longines chrono is for sure all about the movement and thats why when it comes to the chronos vintage must be best. Whilst the Heritage edition is clearly a nice watch and very attractive in it's own right, it's maybe too far removed from the spirit of the original.
By way of contrast, the Longines Legend Diver seems to be much closer to the spirit of the original. Not only are the design and aesthetics beautifully re-created but, as far as I know (and I stand to be corrected), some original versions of this watch had a movement based on an A. Schild movement and so the use in the LLD of an ETA based movement is much more appropriate for this model. I can't really add to what has already been written about the quality and value of this watch.
Att the last GTG I attended in London in December last year, there was a clear vintage end of the table and a clear modern end of the table. I was at the vintage end - shows where my heart lies! Somehow I could see an LLD being comfortable at either end of the table, but the 1973 would have to stay at the modern end!! That probaly sums it up for me!
Thanks for your thoughts - it's interesting, and prompts thought.
Best wishes,
Vernon.