I think that it's really hard to predict how the INTERVIEWER felt about the interview....it could be completely different from your experience. For example, let's say you are the interviewer, and the applicant is talkative and relaxed. However, what the applicant is saying contradicts his application and you realize that the applicant is full of bs....you can either a. humiliate the applicant by pointing this out, or b. smile, thank him and walk him to the door. In case b, the applicant feels it went well, the interviewer was kind and he talked a lot. However, in reality, it was a bad interview.
I guess I'm just trying to say you never know what the interviewer is thinking.
My worst interview, I thought it went horribly. I was pounded and grilled by my interviewer and forced to admit that I just didn't know about certain issues. I was questioned on my values and he was openly incredulous about my answers. I was 100% positive that a rejection was in the mail....the acceptance came 2 weeks later. I guess this interviewer's goal was to see how I reacted under stress and if I stuck with my answers instead of telling him what he wanted to hear. By being myself, I passed the test!