Just had a Sherwood Oais serviced. Reg is about 10 yr. old, never noticed it hard to breathe. Tech said intermediate press. was 125#, changed spring, added shim, and raised to 135#. Do these press. sound right ? Going on a 1 week trip off Kona in June, now not sure wether to buy new reg.? I dive mostly warm waters with force fins and have been known to tire in moderate currents. Always assumed short fins and large body mass to blame, now wondering about air flow. Any thoughts.