At the risk of being redundant with what's already been said. I've had good and bad experiences with stage-lip. I use it almost exclusively wiht instrumental bands (mostly jazz), but even at that, I've found that you're really at the mercy of how the mix is coming out on stage. The PA plays a bit of a buffering role if you will, compensating for quieter instruments, so when you move beyond the throw of the PA, you lose that buffer.
Case in point. Taped a jazz quartet the other week (Bari-sax, drums, elec. bass, elec. guitar). The horn player, Ken Vandermark, tends to play LOUD, but it happens that the rest of the band played even louder. During the quieter parts the mix is fantastic. Great stereo imaging, nice "up-close" feel, really everything you want from a recording. As soon as they got to the noisy improv sections though, you lose the horns in the din of the amplified instruments and the drums. I re-balanced the recording to compensate, but it wasn't enough, especially with omni mics. You can check out a sample of the quieter stuff right here if you like:
http://www.dimeadozen.org/attachments/203005/2607926/powerhouse2008-06-27t5.mp3