HiMD: mic vs. line, setting levels, preamp headroom?

[poorlyconditioned]

I'm used my NHF-800 a few times for live music recording. I've used it in most modes (MD and HiMD media, and SP, Hi-SP and PCM modes, and with both Mic and Line in). Overall I like the extra flexibility. I can get really long recordings in Hi-SP (no disk changes!) or excellent quality in PCM.

So, how "abuse" can the mic input take? When I go to loud shows I use Line in and turn the gain up to maximum (30/30). I figure even if I lose 10dB or so in level I save by avoiding the mic preamp. But for mid-to-loud shows I have to decide whether to use mic or line input. I've recorded at moderately loud shows without noticeable distortion (mic in, low sens, 18/30 setting, and levels upto 0dB). I'm guessing that anything louder than that may distort mic in. But I haven't tried it yet. My mics are AT853 (approx. -45dB sensitivity).

Thanks for any help,

Richard