It doesn't really matter -- VP debates, as a rule, have no discernible affect on the race's outcome. The objective is to get out of it without doing harm to your side's ticket.
Did Ryan win? Some say yes, some say no... I don't care either way. He did his job of "do no harm".
But Biden? Well, he had a secondary goal of playing to his wavering base, and by all accounts I can see, he was successful there. But his "smirks and laughs" routine played very poorly (and indeed, the RNC capitalized on it immediately with a devastating web ad [get this on the air in swing states now!]), and he may have violated the "do no harm" directive.
I concur with your assessment. Well said.