I tried switching to Castrol GTX 5W-30, but my oil pressure still drops to about 15PSI at idle when the engine is warm. I'm not getting a CEL, so it must not be that big an issue. I would try using a heavier oil like a 10W-40, but I already get pretty high pressure when I'm at high RPM. Looks like there isn't a difference between synthetic and conventional in my case. Keep me posted on what happens for you guys.

BTW, I agree they have poor quality control.