I have an H balanced p-valve. It almost never leaks. Maybe once every 200 dives I've had to take out the duck valve and give it an extra good rinse, but certainly no leaks in between those times. Do make sure you aren't over-tightening the plug that seals the duck valve. That seems to be the number one cause of problems.
Been through all of that with Halcyon, no change in the leak.