Saturday's New York Times gives me more reason to like Biden:
Top aides say it has become customary for Mr. Obama to solicit Mr. Biden’s opinion at the end of meetings. But his views by no means always carry the day. At one January meeting to discuss the budget, Mr. Biden railed that the government was in no fiscal shape to pursue a health care overhaul this year — to the dismay of many present and others who heard about it.
The vice president later backed off, but Mr. Obama — who disagreed strongly with the view — has come to see Mr. Biden as a useful contrarian in the course of decision-making.
Rahm Emanuel, the White House chief of staff, said that "when there’s group-think going on, the vice president tends to push the envelope in the other direction" [Mark Leibovich, "Speaking Freely, Biden Finds Influential Role," New York Times, 2009.03.28].
The useful contrarian—my kind of role! Note that in the example cited here, Biden is arguing against a reform dear to my heart... yet I can respect him for being the voice of dissent in the room.
And how does the President feel about disagreement from his Number Two?
“There’s, I think, an institutional barrier sometimes to truth-telling in front of the president,” Mr. Obama said. “Joe is very good about sometimes articulating what’s on other people’s minds, or things that they’ve said in private conversations that people have been less willing to say in public. Joe, in that sense, can help stir the pot” [Leibovich, 2009.03.28].
Stirring the pot, questioning the boss: that's my kind of loyalty.