IMHO, your particular 'concrete criticisms' to this point are all part of the media circus. Consider yourself as having been sucked into the American partisan political system. Blatant, dogmatic criticism of either Biden or Palin (or anyone for that matter) is no way to try and win another vote for your side. Unless that isn't your intention and you just like hearing yourself talk...
You are still criticizing me - what did you think of THEIR performance?
I will give you something to comment on since it seems like you are having trouble of thinking of anything on your own.
I was actually thrilled to hear that Palin supports the Obama/Biden bankruptcy reform policy. But it turns out that McCain does NOT support their plan. Does she just disagree with him? Is she just uninformed on his policies? Either way, I don't think that mis-stating her running mate's policies puts her in a good light.
I was also thrilled to hear that she supports civil unions allowing gay people to enjoy the same rights as other married couples. And here I thought that Palin was a social conservative. Did she change her mind on this issue? Or is she just saying it because she is on national tv?
I thought that one of Biden's strongest moments was when he pointed out that while the McCain health care plan offers us a $5,000 refundable tax credit to purchase health insurance, he also wants to make the benefits that I receive through my employer TAXABLE. What do they say about things you want less of? Tax them? So McCain's policy is actually aimed toward REDUCING employer-provided health benefits, and forcing more families to purchase insurance on the open market where it is more expensive and harder to get. I was pleased that he made this point so clearly.