Long post alert!
GSPs here. They've been out-of-the-box hunters with solid pointing, search, and retrieving. Mine don't want to play fetch with a ball, but they desperately want that bird in their mouth, so that helps. I think they were the perfect fit for me as a novice bird dog guy. With only basic commands you can have yourself a very serviceable dog. They were an adjustment at first because of their range - I was uncomfortable with them being out of sight and tried to constantly reel them closer at first. Over time, I just let them go. They'd check back often enough to keep track. E-Collars were a must though, and a Garmin would've been very helpful at times. Mine were/are very independent and more self-hunters than teammates, but things basically work out most of the time. It would be hard to mess up a well-bred GSP assuming the owner isn't a complete jerk.
They're a very forgiving dog. Hardheaded is not necessarily a bad thing at all. I made plenty of training mistakes, but they basically shrugged them off because they had one thing in mind and that was to find birds. Mine were/are a little fur sharp - a few bad encounters with skunks and porcupines, plus a love for rabbits. It was a bummer in those instances, but I've been able to haze them off of the undesired critters enough to keep things at bay. I hear about the fur drive in DDs and PPs and have to wonder how much more it could be than with the GSPs I've owned. Can't be much in my case.
Mine haven't been strong water dogs, which for some would be a real issue. I'm not a waterfowler, so I don't care. If i'd taken them to the lake a few times early in their life, it probably would've been just fine, so i can take some of the blame there.
My dogs have been productive, low-maintenance, and healthy. The downsides have been the energy, which in comparison to some other high-octane breeds I've been around has been noticeably higher. They're not a dog for the cattails, and who knows where the hell they go in the woods, but for me in open country they've been really great. Very loving dogs too after plenty of exercise. Their soft ears and cuddly ways make them a hit with the family, and their looks are about impossible to beat. Like springers, they're very optimistic dogs. Happy all the time and ready to go 24/7. Tolerant with other dogs and kind but slightly aloof with strangers. A good fence is important - they'll chase a squirrel or a rabbit a long ways if given the chance. We've had a few white-knuckle moments over the years dealing with stuff like this. It's not pleasant when it happens.
Not for everyone! Lots end up in shelters due to owners being overwhelmed. I've passed up on more than one really nice prospect in shelters because I had too many dogs at the time, so good ones are out there to be rescued. You can also pay $3000 for a pup from one of the higher-profile breeders and you're likely going to get a really good dog with health guarantees and a long line of strong genetics. I'm far from an expert in the breed, but off-hand I know of several kennels that I'd be happy to get a pup from, so availability is a plus. I'm into the NAVHDA bred variety.
As a slightly more seasoned guy now, I could see the allure of a more moderate dog in every sense. I'm not sure what that would be, so I'm always looking, but it may be unwise for me to go any other direction because mine have worked out so well overall. Lots of breeds in the running for a potential replacement - DD, PP, SM, EB, EP....you name it. I always seem to find a way to circle back to the GSP as a top contender. Decent heat tolerance, cold tolerance, low maintenance, great retrieve, stylish, beautiful, friendly, (a little hyper at times), high-drive.....jeez, lots to like. If somebody bred SM or DD temperament (these dogs can be really calm in comparison) with GSP everything else, that would be the golden ticket. Somebody might say - 'look at the DK' - I might have to do that. Those dogs run a little big for me though.
Ok that's enough. Overall I'm satisfied with the breed.