I'd like to get either the DR-40 or the DR-100mkii but one of the things I would need the unit for is recording lectures and speeches. Are either of these sufficient without external mics and preamps? Would you feel save putting the DR-40 in a town-hall setting to record what is going on?
I often go to political meetings and I just want something fairly discrete and easy to set up that I can record the speaker with. Then if I want to interview, I'd like to use an XLR input and the unit at the same time to conduct an interview. I think either device will be plenty for the interview-need, but do either of them have sufficient mics and pre-amps to record a speech?
That class of audio recorder is going to be more than adequate for recording lectures and speeches. Your main limitation will be that you have a pair of microphones far from the speakers, so you will pick up the ambience and reverberation of the room. But that should still be adequate for personal use.
If you really want to be discreet, then you might want to consider one of the recorders that looks more like ordinary consumer electronics. The sub-$100 recorders are usually small and thin, and the Sony M10 looks vague like a cell phone, particularly the red version.