"I'm not convinced that the best instruments are the fine old masters instruments, and I have played on the real deal a few times"
For what it's worth I concur, people have always believed that the Strads and the such were of almost mystical in performance and sound, how ever today we have extreamly well made violins now coming from all over the world with plate tuning and experimentation on resonance computer imaging CT scans to replicate plate graduations etc. But it comes down to a listeners preference in sound and color is to the listener ears, several top concert violinist have stated some strads sound good others sound bad, some project some don't. If I owned a multi million dollar instrument I would want it to have a sound that a modern instrument could not attain so I would not lose the value of the investment. I've read where Kreisler, would at the request of orchestra members take there violins and play them and there instrument would sound fantastic in his hands, I watched a video of the Luther who took care of Heifitz violins for decades and his statement was after Heifitz death he heard Heifitz violin played by another violinist it did not even sound like the same instrument. It's the person playing the instrument that brings out the sound of the instrument, good or bad, in reality an instrument is a tool to create music, it up to the player it make it sing.
My personal observation.
Master the Frog and you have mastered the bow.