My car is running well, but the boost seems to bleed off starting at around 9-10 psi even though I run up to 16 psi.

The layman's version..."it does not feel like 16 psi."

Sometimes I wonder if my BOV is working at all. All I can hear on throttle release is the WG.

 

do your intake temps rise a lot after a long pull? Why dont you take off the vacuum line to the bov and see what happens. It may be adjusted wrong and bleeding off boost (watch the turbo gauge carefully while doing this) Just don't slam the throttle closed after full throttle let off of it very slow....so go until 6500rpms so you still have some rpms left to let off slowly