Now since you don't seem to like math I figure I would post this before you come up with something to make yourself look foolish, the general consensus is that 10SS = 0.01 off your GCD, meaning that 1SS = 0.001, multiple that by 1000 and you get 1, a full second shaved off your GCD for all spells. As I stated before this is not a %, its a set number which is why your "raise" only gets around a second shaved off its casting time. So assuming you have around 500SS via gear when you use PoM you get almost a full second shaved off its casting and recast time, provided those numbers are 100% accurate.

There you go, math.