I love love love the Sony PCM-M10 but its internal mics will not be able to handle the kind of blast-level volume the OP will be attending.
Before I bought mics all I had was the PCM-M10. I regularly put it on stage 6-10' away from amps and got good recordings. They aren't spectacular, but certainly better than no recording at all and as has been stated, the M10 is a keeper.
I didn't put a dB meter on it, but I'm talking about recording Jon Dee Graham, Javier Escovedo, Alejandro Escovedo and the True Believers as a whole, and in their electric versions they definitely know a little bit about being loud.