Chessies

The Chessie I used to take care of was a good guard type dog, much more so than your average lab or Golden.  He seemed more aloof, dominant, and alert.  He did drool and shed a lot.  He was 115lbs so quite formidable but I think he may have just been huge and fat.

I've spent some time around Chessies and have trained a few for bird hunting, both dove and waterfowl. Chessies taught me just where the holes in my training were. lol  The breed is quite different from the other retrievers, in some respects.  They make effective watch dogs.  They can hunt all day and trail riding would be right up their alley.  Very athletic dogs with tons of stamina.  I found them more unforgiving of training mistakes than Labs and Goldens. Trainers sometimes consider them stubborn but it's often a case of bad communication.  Chessies are thinking dogs, more so than Labs and Goldens. The ones I knew could be aloof with strangers but formed tight bonds with their families.  They do shed and have a dense, almost oily coat.  They would be fine around cats or small dogs if properly socialized.  I don't think they have experienced the huge field/show split like Labs and Goldens but there are certainly lines that might have been bred more for the ring than the field.  I think he could do much worse than a well bred Chessie from lines with a few field titles. 

Working Retriever Central is a good source to search for a breeder.

I've met a few Chessies and found them to be more serious than any other retriever I met. They were affectionate with their family and aloof with strangers. VERY smart dogs.

I've met several field bred labs over the year and found them to be great dogs. Smart, friendly, not sure about how guardy they are though.

I can say that if your Dad is looking for a more serious dog, a Flat Coat will not be a good match. They are silly dogs, sense of humor and they remain that way for a very long time. They are smart, but mischevious at times. As Ari's breeder put it, they have "flat coat moments", in which they decide to do something routine, but with a twist to make it more interesting. Her example was retrieving game. Instead of coming straight back to you, they may decide to make an obstacle course of it and take the long way back, just because it's fun and hopefully their human is laughing.

They are also not an imposing dog, as a Flat Coat tends to greet everyone with a happy face, wagging tail and a billion kisses. However, they are great alert barkers in the home and their barks are imposing. There's not too much difference between those bred for show and the field, since their gene pool is so small and those breeding them are doing their best to keep the breed true while improving it (cancer is a serious concern in the breed and it hits them young) If a Flat Coat is still in the running for him, I could likely put you in touch with Ari's breeder to discuss the breed further. She currently owns 4, shows and is very active in the Flat Coat world. She loves talking about them.

 A friend of mine owns a chessie - he's her husbands hunting dog. The dog also lives with two poms, a terrier mix and a few cats - with no issues. I've never met him personally - but the owner brags about him all the time.