Hi
Cosmetics are different as Pro only comes in Black Rack-Mount faceplate versions and the gain controls as you said.
I usually recommend the Consumer if you want the simplest circuit path (no gain controls in the circuit) and the Pro if you need to adjust the gain.
james
1. With the PRO level set at 0, I'm assuming you essentially have a consumer version, just an extra circuit.
2. 4B SST2 PRO, serial number 007669 equates to what Manuf. date? The box is sealed with only the serial # showing.
Thanks