A tad slower yeah. Sometimes you need to slow it down live to make sure you can properly phrase the vocal without "tripping" over the words and also give the performance a bit more weight. You're always dealing with nerves and adrenalin live.
biggest? everybody has their own inspiration but if you think they are not the best band tell me somebody who's better has better songs better artists somebody better than john bonham singing better than plant in his prime a perosn like john paul jones playing multiple instruments and jimmy page who's one of the best solo guitarists ever in rock music.
