I have been using SMC for a long time and I have had no problems. I am selling some if you need 16 - 1/2 NPT to 1/2 line. Male connectors. I never used them, I just decided to stick with 3/8 valves. Check out my SSM posting:
http://streetsourcemag.com/classifieds/XcCPViewItem.asp?ID=6474
I have some pics if you want.