I've never used the Edirol R09HR, just the plain R09.
However, I love the M10. What I do is keep the unit in my shirt pocket, facing inward, towards me. I can quickly look down at the LEDS on the top. I'm looking for Green (signal), and just drop the volume if they go Red (overload). If I'm sure of the levels, I just tape the wheel with a bit of gaffers tape.
If you're getting just one unit, I highly recommend the Sony. It works great for both ambient and live music recording. I usually just set the level to #4/10 or so, and the only control I adjust is the high/low sensitivity. You'll discover pretty quickly what level works for your given mic setup. And, as mentioned earlier, the battery life is outstanding. I just leave the unit on always, and lock it when not in use.
Richard