I have one of each. If you want to see them I'm the field, search MissedAgainYT on YouTube.
LINK:
MissedAgainYT
Disposition: Both are exceedingly friendly, but in their own way. PP has a lab personality, has to be with you and touching and goes nuts for attention. DD is happy to just be around you. You could call her more aloof, but that isn't quite the right word. FWIW, I would leave my DD with my neices and nephews and have zero worries, she is the sweetest dog with kids and seems to know they require a softer touch. Both have a great "off-switch". Even at eight years old, the DD is the first to start playing with pups and old dogs alike. It's really funny. The PP has knocked toddlers over, but that was just because he has no sense of the space he takes up. DD tend to have better coats, PP can really be all over the place.
Training: DD was incredibly easy, she came out of the box a hunting machine. Could take pressure, and learned very fast. She was my first gundog, and she dragged me along while she got her NAVHDA VC. PP was a softer dog, took more care in training. That being said, he's a 204 UT dog, and we'll see if he gets his VC next year.
Hunt: DD is an incredibly cautious hunter. Range is dog dependent, not breed dependent, but DD is a closer worker. Her disposition in the field is all business. I truly think she wants every bird to die, and is slightly upset when we leave without getting them all. PP is a bigger running, flashier dog. His points regularly make me do double takes, but I think his thought process is "I just want everyone to have a good time", whether we find birds or not. He's just a goof. Both are great retrievers, but the DD has more drive after the shot. DD tracking ability trumps the PP.
Find a breeding you like, and you'll be happy, regardless of the breed. They are both great dogs. DD gives you the ability to go in "blind" as their breeding requirements are so strict. PP breeding is, unfortunately, less reliable. Go with a NAPPA breeder, and you'll be good. Some breeders go for octane and range, some go for cooperation and mental stability. I've seen PP and DD that I wouldn't ever want in my house, but most of those made sense when I looked at what the breeder was going for.
Best of luck.