Mary- I missed this discussion, but I have to comment on several of the breeds that you have on your list. I would NEVER call a Portuguese Water Dog mellow...brilliant, energetic, sweet, but not mellow. The PWD owners that we know (and train with) call them perpetual motion machines! Ditto for Standard Poodles. Bright, energetic, and friendly (though I find them much more aloof than Berners). I would also include a caveat about the Welsh Corgis: there are 2 types, and the Cardigan is quite active, and a bit more distant than the Pembroke (Cardigan has the tail, Pembroke does not). Corgis also can be quite active, and yappy, and they are very pushy dogs (much more pushy than our Berners, though they both are cow herders). We have had Pembroke Corgis before, and they are very smart, and quite sweet, but the most hard-headed, stubborn dogs we've known. So a person who doesn't want to butt-heads with a dog would do well to avoid them.
Although I'm not surprised to not see them on the list, we decided on Newfoundlands to add to our lives, since we love the size (and don't mind the grooming & occasional drool) but wanted a less pushy and more mellow dog than our Berners. I love the alternate breed list idea. We'll have to copy the list and share it when folks talk to us about what breed is right for them. Ellen (and Livi & Bella, who are adorable, rowdy 8 year-olds who never plan to get old <g>)