Just back from vacation - figured I’d toss in my 2 cents.
Initial disclaimer - I’m a golden fan. AFAIAC, their personality cannot be beat, which makes up for any grooming/cleaning problems caused by the hair. Which I have not found too significant. But, you have experience and a firm opinion on the topic.
Many people discuss goldens and labs together. I have met and known many wonderful labs. But I have to say that I have met some labs that are a total pain in the ass, but have never personally met a really objectionable golden. I’m sure they exist - just I have not met them. Also, many of the labs I’ve met and disliked may have suffered from poor training. But I have heard of far more frequent and more severe destructive behavior by labs as puppies/young adults than goldens. And my perspective is that some labs tend to be more rambunctious as adults, and their solid body and tail can get in the way more, knock down toddlers, etc. Labs are probably a close second or third choice to goldens for me.
Also, with respect to goldens, look at smaller ones bred for field trials, rather than the huge chunky ones that are so popular. my current dog is maybe 60 pounds dripping wet. I’ll have to weigh her.
But, you said you had goldens and don’t want another.
Of the dogs discussed, I’d recommend Wheatens. Again, concentrate on the personality. They are just about as friendly as a dog can be. I have NEVER met an ill-tempered Wheaten. A very manageable size as well. If my next dog isn’t a golden or a lab, it might well be a Wheaten.
You asked about Brittanies. IMO extremely attractive dogs and a wonderful size. Big enough to be a “real” dog, but small enough that the wife could pick her up and bathe her in the utility sink.
I had one briefly and gave it away. The dog loved me as long as I was working her. You could not wear that dog out. You don’t have to hunt them, but they love it. Dinah pointed instinctively. She also hunted and killed mice, rabbits, possums… But she was very aloof, and did not seem to bond with the family. For example, if we were reading or watching TV, she would not even be in the same room as us. And she caused some damage in the yard. She was an incredibly impressive beast, but not the companion I desire in a dog. So I gave her to a friend who has a farm. She is very happy in her proper element.
Other folk have mentioned Viszlas (sp.) I have known several. Like the Brittany, I consider them beautiful and a great size. I am not terribly familiar with their personalities, tho. I understand they really want a lot of exercise, and the ones I know don’t strike me as overly affectionate - which you might consider as either a plus or a minus.
A couple of people mentioned Giant Schnauzers, Dobes, Staffordshires, Rotts, and pits. I like all of these, tho I would shy away from the GS as I have known a couple of aggressive ones. One slight possible problem is that other people tend to (unreasonably, IMO) fear these breeds. Hell, some folk act as tho my stupid golden is going to pull a Cujo and go for their throat. So you might want to consider how it will make you feel, if you are walking your dog, and people you meet act as tho you are threatening them with public enemy #1. Not a determining factor, but possibly relevant.
And tho I love massive dogs, I personally have a hard time with their generally shorter life expectancy.
I’m not sure whether I understood that you definitely want a purebreed. But I’ll mention again the possibility of a mutt. I’ve known some really nice and really attractive lab, golden, and shepherd mixes. You might want to make a shortlist of the breeds that you like, and then keep an eye out for mixes that contain those breeds you like.
Have fun!