i really don't think the crowd notices one way or the other, so why not just pick a tuning that the whole band uses and stick with it?
i always joke that here in virginia beach there's a city ordinance requiring all cover bands to tune a half-step down, but we do it too, so we can save the singers' voices and open up the range of what we can pull off.
songs that were originally played in standard get dropped a half-step, and songs that were originally a half-step down get played the same. (we can usually figure that out by listening for certain guitar chord voicings or low open-string notes).
no way is it worth bringing out extra guitars or trying to re-tune all the strings between songs. it's also silly IMO to take a song that naturally falls under your fingers in its original tuning and try to play it in the original key with all the instruments tuned "wrong" for that song.
not so big a deal for bass players (especially extended-range guys), but for us guitar players, we lose all the chiming open-chord voicings and clear low-string tones that are often in the original version, forcing us to play dumb-sounding closed barre chords up high instead.
pop-rock stuff is not like jazz or blues, where you pick a song, pick a key, and off you go. the specific way they were originally played on guitar (and often bass too) matters much more in getting the right sound of the song.
if we were in standard, we would just transpose up songs that were originally a half-step down, assuming that we could still sing them.
No I don't want to make it any harder on myself, which spurred the original question. I'd rather play the song in the original key, because I think it sounds right. When you start transposing something gets lost, IMO.
