Correct me if im wrong. THe R395 does have an adjustment knob on the side.:blinking:
The R395 has a knob for Dive and Pre-Dive, this keeps the regulator from free flowing when you jump in. The adjustment knob everyone is talking about, adjust how much resistance to start the flow air once you inhale. This allows fine tuning of the regulator without going to the LDS for tuning. The R395 will be adjusted by the LDS to tune the breathing restistance.
I would pick the Scubapro as my preferred regulator.