Offshoot from my "rough year" thread:
My drummer often complains that we play everything too fast. He's big on trying to keep tempos as close to the original recordings as possible.
I tell him I'm much less concerned about tempo than I am overall groove. I view tempo the same way as I do key: you pick the key where the singer will best sing the song, regardless of what the original key may have been. Same with tempo: if the band grooves better a few notches faster or slower, then so be it.
His response is we need to make the groove work at the tempo HE sets (which, admittedly is almost always VERY close to the original recordiing. He's got an amazing knack for finding those tempos) and not let the song veer faster or slower simply because some of the other musicians might be "feeling it" at another tempo on a particular night.