I do not disagree with any of the above posts. My personal experience of clumbers is limited to the two I trained , a bitch and a dog called "Big Ned." I have seen a few other clumbers out working but none of them were a patch on Ned. Ned would retrieve all day long if allowed to and gawd help anything that got in his way . I once tied him to small sapling growing on top of shale and soil.
I threw a dummy for another dog and Ned decided he wanted it, so he went for it taking the wrist thick sapling with him roots and all ! He had a lovely soft mouth and loved retrieving game above all else .....apart from running -in !
As a hunter he was as good as most springers but not as fast as a field trial standard springer. Ned had no fear of cover, I don't think he knew it was there. He didn't so much go through it as take it with him !

I loved that dog and so did my wife. Ned was a perfect example of the perfect housepet and he just ignored my cocker Charlie's attempts to bully him . My cockers got on very well with him , Ned was completely non-aggressive and that came from his certainty that he didn't need to prove himself.
In size Ned wasn't really much bigger than a really big springer ......nothing like the ponderous show ring brutes that can weigh as much as 80 lbs.
In training I found him to be more stubborn than a springer if he didn't like the lesson and he was very strong in both body and mind.
It is vital with this breed to choose where and who you get it from very carefully before buying a pup. The breed does have health issues but maybe not so much so among the true working types ....possibly due to them weighing so much less and to the owners of the work types thinking a bit more about grass seeds etc. getting into droopy style eyes.
Since having Ned I have been told by people interested in using him at stud that he is not as much of a "once off" as I had thought.
Apparently there are some really good clumbers on the go now. One of them won an A.V. Novice trial I'm told while competing against springers and cockers.
I enquired several months ago about getting a pup from Ned and a good bitch. The mating never took place as they are too closely related and the clumber working stock is "tight" enough as it is. I have now got a springer pup coming my way .
Taken overall a springer pup is more likely to deliver a hard hunting, keen retrieving sort of dog than a clumber pup is ......but I'd still love to own Big Ned.
Wullie