My thinking is this, we are playing in front of a guy who's been playing practically his whole life. (Dave) Who could possibly be a greater critic? Someone with half of his time on a fretted instrument? A third? A handful of us have that much time playing consistently at that level. We are basically all in the same pot as students. We are here to learn, and i happen to learn from listening to my playback. It takes me out of the first person, and puts me outside, in third person. Chances are, if i don't like what i hear, quite possibly no one else will either! Play it back, compare it against the music, was the timing good? Listen to the playback with a metronome, listen for the thump on the bass note of the chords, did the chord changes happen at the proper time in the measure? Did the notes ring, or were they muted? Did another player play out of time, by speeding up, or missing their lead? It's really a good idea.