There's a perfectly good -- and, when one thinks about it, moderately obvious -- explanation: when you are listening to someone else, that's exactly what you are doing and what you are paying attention to. However, when you yourself are playing, most of your thinking is going into controlling your playing, and you are only hearing enough of it to keep track of what you are doing. You are not listening in the same way at all!So yes, recording one's self can be very helpful, absent usable feedback from qualified people. It can also be a bit disconcerting...