Hahah. That would be a compelling reason indeed!
Seriously though, having both units myself, I did have a couple scares with the D50 and security because of their use of metal detectors for the first time. Thing is, security are generally oblivious to such devices and in my case, I simply wrapped my mics around the unit (in its Sony leather case I bought with it), held it in my hand doing the Jesus pose while they scanned me and never said a word to me about what I was carrying.
Nevertheless, the smaller you can go, obviously the less likelihood of you being hassled. In which case, despite the PCM-D50's mics having a noticeably better sound in my opinion, the PCM-M10's mics aren't that far behind and you'd still do pretty well with them as far as internal mics go. I've never used them in a rock environment though so I can't really say for sure if they'd do well at handling high SPL's but of the few louder jazz gigs I've experimented with, they seem to fare nicely. At any rate, for your application, I don't think you need to go as far as the PCM-D50. Get yourself the PCM-M10, enjoy it and get yourself some good external mics when you can.