I am not saying recording from a stage can not yield a good tape but its never going to be as good as the best out front mix.. Thats All I am saying
I am jumping into this discussion a little late, and I heartily agree and disagree with various aspects of different posts. I think that Chris' quote above actually sums it up pretty accurately. I also love to tape on stage, but preferably behind the monitors under just about any situation. If it is a non-vocal band, a la Kimock and many others, with good mic placement, you can produce phenomenal tapes, with instrumental clarity, along with lack of audience noise, room boom, breaking bottles, etc. If you happen to be fortunate enough to be in a great club, with an excellent PA, and a great sound engineer, and there is an ideal taping location available, you can hoist your mics, and the crowd is somewhat respectful of the music, then yes, this could well be the dream tape. Unfortunately, I am not usually at these shows. Many PAs are lame to downright awful, with say a nice buzz coming through one channel. Too many sound engineers are just plain deaf, and as far as I can tell, can barely distinguish between various high frequency sounds and balance them in the mix. Many smaller rooms are iffy at best, too narrow, poor PA placement, or limitations on where tapers can set up. I am not talking about a high quality room here, but a lot of run of the mill rooms, in which many of the small to mid-range drawing bands play. In those rooms, with an instrumental band, you will find my stand front and center. In a GREAT room (wishing there were more here) I will agree with Chris.
I also would like to comment about one of my pet peeves about on-stage taping, which is mic placement. Dead center is just not the answer for every band, and people seem to slavishly want to get out a tape measure to plant their stands there, no matter what. If there is a big drum kit in front of you, on a shallow stage, then the drummer is going to love your tape, but not too many others will. Many times, the stand needs to be moved left or right to ensure that the drums or bass don't completely drown out the other instruments. Since every band sets up differently, you really need to survey the situation, and place your mics accordingly. Rant over.