not what I'd call fantastic. I haven't shot enough with other cameras
to make a comparison. If it has a gain up setting, I'm not aware (and
I shoot a lot with it), but cameras that effectively give you a gain
up effect with a shutter speed give you that pixellated look when you
move the camera (which is sometimes nice, but not always). As for
manual whitebalance, it has no affect on low light shooting.
Anyway, my gut reaction is you take your own advice and use the
excessive grain as an aesthetic. Could work very well.