Well, my two cents.
In any recording I aim for low enough volume to 110% sure of never going into clipping. Digital clipping sounds awful. On the low end, I want to stay off the noise floor. And since the 722 has a decent S/N, it seems quite OK to aim between -20dB to a maximum of -10dB for the peaks. Exactly where the meters are the most detailed.
Once the recording is done, I transfer it to my PC and do a "normalise". This will set the absolute peaks to exactly 0 dBFS by increasing gain. Generally I will do a bit of compressing as well, but that depends on the source and the sound I aim for. When aiming for that contemporary CD sound, it would include going into a limiter set at -0.3 dBFS.
Gunnar