1. One of the trials was an underage rape case and there was essentially no physical evidence. Mainly all we had to go on was 3 police interviews (2 from the alledged victim, one from the accused). As a jury, we relied on those videos to determine who we felt was telling the truth and the trust worthiness of what they were saying. I'm not saying this was a good thing necessarily, just an observation that this is what we did. I'd like to see the results with a parallel jury that relied only on written transcripts etc.
2. The judge actually gave us guidance at the beginning of both trials that in addition to what witnesses said, how they appeared to us (their demeanour) was also evidence that we could use in assessing the trust-worthiness of what they said. My understanding was that we should use our general life experience that we had acquired in our day to day living to assess the evidence of the witness. I guess there are good sides (eg. intuition based on non-verbal communication/body language) and bad sides (eg. biases) to using this approach.