that is true, ive ran em both. The 1/2 is definately the better way to go. Even tho they are rated on 150, the 3/8 start sticking if u have about 200psi in ur tank. If u wanna go the safe route u can get GC450's. No probs yet and niether have any1 else i know running em.
smc makes 2 3/8 valves,,the 150s will stick if ya go over 200 psi they also offer a 400 psi 3/8 valve they wont stick ,,the 1/2 valves are kick ass also,,,all i run is smc again,,,i tried a few other brands and came back to smc,,
as always, 99.9% of the valves out there will not run well over there stated max pressure. but i would stick with SMC, they are the only valves i have ever used. i even ran some 1/4" from them. they were as quick as a 3/8" up, and a bit slower down. i thought they were perfect.
i have 8 3/8" smc's on my truck on 175psi, and never had one stick. About a week ago I got my first leaky valve in 1.5 years of daily driving, so I ordered a replacement