Works better than any I've previously bought and didn't cost anything. Currently set at 18psi, with a 4.7v zener diode installed on the MAP sensor to prevent overboost shutdown. I'll be building a boost referencing driver for a 5th injector installed in the throttle body this week. At 18psi the EGTs get a little higher than I like after long pulls. A small injector to open up at 14psi will cure it and I won't need to retune.
You can see the adjusting knob to the left of my master cylinder here.