I always felt, as a listener at a show, that when there was too much banter between the artist and the audience that it detracted from the show. I more enjoyed shows where the guys came out and they just played.
Trust your gut instinct over spreadsheets. There are too many variables in the real world that you simply can't put into a spreadsheet. Spreadsheets spit out results from your inexact assumptions and give you a false sense of security. In most cases, your heart and gut are still your best guide.

