Unfortunately temperament and good health, the two really important factors for a good relationship and enjoyable ownership, all too often (thankfully not always) seems to come after looks and profit when it comes to dog breeding, with occasionally some expert handlers very effectively covering for poor temperament and aggression, allowing dogs to become champions with associated high demand for their puppies .

Have you noticed how puppies are advertised as having "good temperament" without specifying what is meant by that?

Yes I am always surprised when I see this advertised as it would be strange to come across a young pup with a bad temperament surely? I would be more interested to see what the dam's temperament is like myself.

Someone at work whose Dad has a Kerry that is dog aggressive said that when the Kerry Blue won at Crufts it bit the judge and he laughed and said that's what he expected from this breed! Awful if this story is true.

The breeders in Kerries seem to cover poor temperament by using the word "gameness" to describe it in my opinion.
Parker is very soft for a Kerry and fortunately has had excellent health too and you're right-this is much more important than how he looks (though he's very handsome too! )

I would say you don't see OES or Samoyed's as much now but they were not hugely popular before - just don't see any now. It's more a case of which breeds have become more popular here tbh. In that case its Labs and Staffs.

I had that in mind but was avoiding mentioning it as is about a specific dog but as you mention it : When it was judged I noted the handler held it's muzzle closed with both his hands wrapped around the muzzle and gave it a "look" while giving its effectively clamped muzzle a very firm single "Don't you dare" shake as the judge went over the back end and I thought then "That doesn't look good to me", As you say the dog won reserve BIS, and being a male has no doubt done a lot of stud work.

I was discussing aggression and the canine genome with the gentleman concerned with that project and mentioned my misgivings about this dog and breeding it as an example, and he also confirmed it bit the judge later. He also confirmed they had been unable to isolate an aggression gene.

Fortunately for the owner (but unfortunately for the breed?) as this was outside the class judging it wasn't banned for biting the judge.

I have noted other dogs at other shows (and others at Crufts) that, if you carefully observe the behaviour of dog and handler, are subtly being expertly handled to cover/control aggression issues