thereis no "which is better"
there is only a "what you wanna play"
sorcerer is a class which has mighty skills and the power of controll.
spiritmaster is the one who controlls pets and fights with them...
different playstyles, both are "good".
it says the sm was overpowered but get nerfed. dunno.
sorcerer is good for pvp.
but those are all things you have to make your own image about.