Sorry to hear of your hunting pal, looks like he has paid some dues in the marsh. Here's a cold-friendly for him, :salude: .
I would say that Chessies are generally stronger than Labs; their build speaks volumes. These dogs, by design, were bred for the rough waters of the Chesapeake Bay; their namesake. Retreiving and guarding hundreds of ducks per day was standard issue. As far as their stamina, toughness and a over-all "ready to retrieve" dog, I, of course, count them among the best.
I wouldn't say that Chessies are smarter than labs. I would say that with any type of dog the proclivity for intelligence falls back on the breeder. I have met a Jack Russell Terrier that could probably rate higher than any dog I have ever witnessed as far as problem solving on an agility course. If you want a "smart" dog, Chessie or not, then get a smart breeder. There have been plenty a great dogs bought and sold out of a newspaper but if quality bloodlines are what you are after, then leave the classifieds at home. Bloodlines are what you want here...........the better the blood the better the chance for greatness; Labrador, Chesapeake, GSP, Gordon Setter, whatever.
All dogs are self-minded if you let them. Every last one of them. Say you shoot your first drake pintail that you've been dreaming about mounting for the last decade and you send your dog out on a beautiful retrieve but he pulls up short on you and devours the bird to bits before he gets to you. That dog is pleasing himself. He is doing what he wants to do thereby rewarding himself.
You already know what your going to get with a Lab. As you know, they are wonderful hunters with a great disposition for a family. If your ready to break the mold and try something different, challenging and exciting, then go with a Chessie. Don't worry, all of the non-dog world will think it's a Chocolate Lab anyways.
"It is not the function of our Government to keep the citizen from falling
into error; it is the function of the citizen to keep the Government from
falling into error."