Funny. I have never noticed a difference in the way my reg breaths in any position, at any rec depth. The 1st stage is an unbalanced piston and the 2nd stage is a Hollis 500SE. Inhale and exhale are both easy in any position. Maybe the difference is so small that it's hard to notice.
Funny I hear this all the time and again all regulators conform to the laws of physics including your Hollis and if you position yourself as shown in the graphic you will notice a difference and it it is measureable and I have measured it in years past. The variation is less noticeable overall with a sh reg vs a dh and servo/pneumatic amplified regs mask the variation but it is always present.
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