Reply to Upfaders - Headroom poll

I come from primarily mixing with rotary mixers (I use a Rane MP-2016 these days). These mixers channel knobs can go from 0-10 of course. It's always been good practice that when mixing with one of these rotaries, the mixers sounds best when you keep your channels at around the "8" mark.

This is where the mixers gain structure comes together best, and it gives you some headroom if during a mix you need to boost one of the channels a bit higher. I believe this goes back in time to the Bozak's and UREI's, which didn't have gain knobs per-channel. Essentially, your rotary channel knob IS your channel gain.

On my Rane, things are little more modern. You have the channel fader, but you still have per-channel gains as well. I still always mix around the 8 mark for good practice.

Now, I also have a DJM-900. I tend to still mix around the 8-9 mark, but most DJ's I see using this mixer just throw the faders all the way up. So as a general poll, which do you prefer and why?

And if anyone knows, how is the mixer actually designed to sound best?

Levels are key to proper mixing!