Not very different than normal. I actually do not touch the MID volume anymore.
So, the MID/DSP volume has a default level when you start the car. That volume might not be enough for you. It depends how high you listen to the radio. The level is ok for me. Now, when you use the steering wheel controls both volumes go up and it feels normal increase. If yo use the HL volume then you increase the input volume for the DSP amp which will cause distortion at the very hich level. In my case I use both. So if I want to listen very loud to music then I lower the volume from HL and increase it from the steering wheel controls.

I went in details because you asked but to be honest I already forgot the way am controlling the volume. It is similar to your home entertainment system if you use TV volume and the receiver volume. I think I mentioned in the DIY, you can take the MID volume potentiometer out and wire it to the ashtray if you think you need that handy.
I haven't had a chance to try the new units yet, tonight I will do it for sure although I do not think they fixed the DSP problem.