I don't understand why any Democrat would have sufficient issue with Ron Wyden to vote for a non-Democratic candidate. If you do, you should probably reevaluate your partisan allegiance because Wyden is really damn close to Generic D.
Cuellar I understand the objections to, but I'm not that upset by a bad VP choice, and he's not offensive to my sensibilities even if I disagree with him on a fair amount.
Wyden is somewhat to the right of Generic D on economic issues and maybe a bit too pro-gun. His top appeal to the base is probably civil liberties and most social issues besides guns. I put Cuellar as his running-mate to accentuate that he is not exactly Generic D for the country.
However, Wyden is pretty close to, if not the definition of, Generic D for Oregon.