So let me ask you this. If you were buying a recorder solely for recording a band in a live situation with the units internal mics... you would choose the h2 over the m10? If not either of these recorders then which?
Heh, I asked for that, didn't I?!
Firstly, I much prefer the user experience of the M10 and I'd have to force myself to focus on the final outcome rather than on which I'd prefer to be using.
If it's a loud band the M10 will, I think, clip before the H2 would, but I need to double check on that.
If it's a stealth recording, the M10 is more discreet (eg you can turn off all lights and indicators).
The M10 battery life means you don't have to even think about it. The H2 is no disaster in that department but you would be silly not to start with really fresh batteries.
I record classical music rather than rock, so that skews my requirements.
I guess the overall answer is that I'd probably use the H2 if the best end result was the priority, but I would wish I was using the M10.
As for what's best given a wider choice of device, I'd bow to others' greater hands-on experience. The R09 or the H4N?? Assuming that you don't have a huge amount of cash to spend.