I stumbled on this stand up bit from 2010 and it's pretty good. The Kramer, to me, is spot on... the voice, the mannerisms. The Jerry is pretty good too.

See it here: http://youtu.be/Gq0IaxGX4E8

Anyone else think this is spot on?

That's pretty good! And very funny! I think he over-exaggerated Jerry a bit but it was hilarious!