I dive in less than ideal conditions so I like my regs tuned for mechanical stability. By that, I mean that I give them room to drift and still be within specs for a working reg. What I gave you is the really general recipe for 'stability tuning'.
When you inhale, there is no water in that path. When you exhale, you will need to move a bit of water out of the way.
WOB is a total non-issue for me. Can you mess with a reg to make it a hard breather? Absolutely, yes. But when properly tuned, just breathe deeply and slowly on both inhale and exhale. Just like audiophiles who think that they can tell the difference in gold coated speaker cables, there may be some divers who can tell the difference between properly tuned reg sets. I have better things to pay attention to when underwater. I'll go so far as to say that all modern "name brand" regs breathe fine through the entire range of recreational depths and I doubt that I could tell the difference.
If you are curious and want to pursue this, there are old regs out there that are hard breathers, ask the usual reg guys. They have stories...
