SMC OR GC????

I Just orderd the 6 GC 3/8 Valves from Suicide doors. I Was wondering are they really quicker then the 3/8 smc and will I be more happy with the GC's compared to the Smc's I Ordered 2 SMC valve before I just was waiting to get more money up to order the rest Just jason said they were better and quicker. IS that true or what's the deal with these new "supervalves"?? How much pressure will the 3/8 standThanks!