I have not the time to give a lenghty qualified answer right now (I’ll try tomorrow).
But for a starter, I suggest you read up on the good old VU meter, and learn how to use it.
Why the standard is set to, 0VU = +4 dBu = 1.23 Volt in pro audio equipment (often set -18 dBFS in the digital domain), and so on…
I suspect the cleaner portion of your recording, is first and foremost that you are not driving your analog chain (pre-amp) to hard.
0VU is there for a reason. That level (1.23 Volt) is a standard were the most pro audio manufacturers calibrate their equipment to have the best S/N Ratio (Signal to Noise). The best middle ground between noise (lower han 0VU) and distortion (higher than 0VU) added to the signal. That’s why 0VU is a standard.
The same goes for the newer quality analog emulating plugins (Sonnox, Slate, Softube etc.). See my comment in the 24 vs 32 bit thread.
If you then add that you don’t ever have to worry about missing headroom, what’s not to like.
Most people tend to forget the analog chain, pre converters. This is the most important part, as once you have captured a signal in your DAW you can’t take away whats already there (Whether added noise or distortion).
Not that lenghty, but I think you got all my reasons as well. For the most part anyway 