The students thought Ryan was serious and determined and a bit nervous. They were impressed with his command of the numbers. They thought Biden was rude and a bit disingenuous. From my perspective I thought the split screen undercut Biden, because he was constantly on camera and so when he smirked it was always visible. One other interesting item from the debate - several students could not understand what the VP does. I quoted John Nance Garner (the job is not worth a bucket of warm spit) but that one was very hard to translate.
In preparation for the debate we discussed both the debate process and the way that the US elects presidents both in terms of the electoral college and timeline of running from caucuses and primaries to conventions to the actual business of campaigning. The process is bewildering to many outside the US.
From my perspective both candidates may have done what they needed to do but neither scored a knockout. Ryan was able to introduce himself as a thoughtful, well prepared candidate. Biden did not make any major gaffes and was combative. I think he may have helped to fire up his base. The one thing unclear to me is whether Biden's theatrics will hurt him with the undecideds. The visual to me of Biden - constantly on screen and all of his grimacing and gestures was off putting - but then I am not an undecided voter. David Gergen commented after the debate that Ryan was more "presidential"; while Gloria Borger said Biden was "condescending." Rachel Maddow called it an "insanely kinetic night."