Interesting the purist Blues thing came up. We are a blues band, we play blues songs and we only take gigs with large audiences that we fancy (we don't play much as a consequence). What we are doing is not re-enactment, we are playing a bunch of songs that people will know, we are playing a bunch of songs that only the hardcore blues fan would know but we are doing it from our perspective today.
Personally I want people to feel dazed, confused and wrung out by the end of or set. It should be heavy, it should showcase the talent of the song writers and definitely make people dance.