I've had Cockers, Labs, HWV and now a GWP. The GWP is only just two years old, so still on probation, but here are my thoughts.
The Cocker was a great dog. Far too intelligent for his own good, a real character. Naughty, cheeky, full of fun. Worked well walked up, beating, on the duck. Hated the peg, enjoyed being out on the deer but you had to watch the little bugger. As he got older he started going a bit self employed which meant going back to basics on a regular basis. Just a sign of the intelligence of the breed I think.
The labs are easy. Very trainable, behave impeccably, are very capable, will sit on a peg, retrieve, and if you start them early will track pretty efficiently. Reliable but the are a bit boring...
The HWV was amazing. I lost him 2 years ago. The best dog I've had. I love my walked up shooting and to shoot birds over your own dog at point is a fantastic experience. He would point deer as well, a long way out, he was better than a thermal if you put him in the right place (downwind). Changed my way of stalking, less reliant on the bins and more focussed on the dog and his senses. He got me a lot of deer over his lifetime. The downside was that he was a nervous dog, which sometimes came out in the form of aggression towards other dogs or strangers. Never to the point of biting but he made a lot of noise. Hated cyclists and anyone with a hat on for some reason. He also hated the rain. Super easy to train, rarely had to tell him twice.
When I changed this time I wanted all the good traits of the HWV but a dog that was more confident and more hardy, so I went GWP. I got what I wanted, but in spades. He's been out with me on the deer since 9 months, but it's a bit like stalking with Tigger at the moment. Just too over excited about everything. I'm told by those that know he will calm down between 3 and 4 years old. What he's really good at is walked up grouse. He covers the ground and points much better than the HWV. This year we've done 11 days pointing training on the moors and a walked up day in August when I shot a brace over him for the first time. He was close to perfect. We've worked for other guns shooting over him too and all comment on just how good he is. We did two days grouse counting in July and I walked 12km each day - I suspect he was doing 60km a day quartering 150m either side of me - and he still wasn't tired in the evening. I think when he matures a bit he will be better than the HWV at everything, but it will have taken a lot more work and patience to get there. The prey drive is off the scale and I have had to do a lot of work to keep him off the sheep - and still don't trust him entirely. He's a big strong dog, 35kg of muscle - the HWV was 26kg.
And neither the HWV or the GWP cope well with being kennelled. They are both like velcro, have to be with you all the time.
If I was to liken them to cars I would say the Cocker was a hot hatch, the Lab a family estate, the HWV is a Mercedes and the GWP is a bit like driving a Ferrari. All very different, all good at what they do, just depends on what YOU want.
I love the challenge of the GWP and I do think if I get it right he will be the best of the bunch, but I might go back to the HWV next time as I don't think I will have the patience to do another GWP. Time will tell.