The only point I disputed is that wood cutting boards have active bacteriocidal properties. I've never seen a study that demonstrated this. I did not say this to suggest that wood boards aren't safe. The science says they're perfectly safe, when used properly, but for reasons unrelated to that hypothesis. Like you, I use both. I prefer wood.
Not all the studies I've read agree with one another, but the general consensus is that both wood and plastic are safe, if properly maintained and properly cleaned. Proper cleaning and maintenance is a bit different for each, so we need to know what we're doing.
The Kass study you cite finds that a knife-scarred wood board harbors less recoverable bacteria than a knife-scarred plastic board. Which is to say, wood seems to be more tolerant of poor maintenance. But in any case, it's safest with either kind of board to maintain the thing properly ... which in most cases with poly boards means replacing them often. Unless someone's finally found a reasonable way to sand the things.