if you record at 16 bit, you really have to work to get it as close to 0 as possible, otherwise you get a poor signal-to-noise ratio.

if you record at 24 bit you have a lot more dynamic range to work with, so you don't have to worry as much about recording hot. record peaking anywhere from -12 to -6, do noise/click reduction, normalize to 0, then dither down. while both techniques will end up with 16 bits, chances of getting a clean sound all the way down to the lower bits are better if you start at 24.