I was seated once. It was a very interesting experience. The previous time I was called was a short holiday week and whatever civil case it was we were called for was settled, and we were excused. The last time sounded like a very interesting civil case in federal court, but I became ill and had to ask to be excused and I was.
The time I did serve was for a trial on a rape charge. The prosecution did not prove its case, and we on the panel were left wondering why THE most important witness for either side, potentially - someone all who testified seem to agree was present at the party where the rape allegedly took place - was not called to testify by either side. It put us in a tough position, because we were instructed that we could only consider that which was presented during the trial. We could not consider ANYTHING that was not presented. In the end, we felt that it was a case of consensual relations where the alleged victim became angry with the alleged attacker after the fact and cried 'rape'. Too many things about her testimony didn't add up.