If Rick Hall doesn't chime in PM him.
It's always, always, always more about the individual breeding than breed. That said, the most authoritative word I've seen on the training Labs vs Chessies subject coming from a Carr based, US mainstream training background like Grahm came from Mitch Patterson, who probably had a hand of some sort in the development of more Dual, FC and AFC Chesapeakes, as well as a number of FC and AFC Labs, than anyone I'm aware of. And his observation boiled down to the balance between building on successes or with corrections, needed to be more heavily weighted toward the former for Chesapeakes than with Labs. (The single exception he noted being Dual CH AFC Rudy of Nordais, who apparently was more Lab-like in that regard.)
That's about the best I can do coming from your familiar Smart Works perspective. (A serious amateur pointing dog mentor, George Bird Evans, started me down a very different, I believe easier on all involved, training path 11 of my 12 gundogs to date ago.)