hi,
my 2 cents follows.
any ecu is remappable, well almost any. it just comes down to how much its going to cost. dr drift could remap your microwave if you like. r32 is easy remap. r33 is expensive remap. r34 is easy (apparently) remap. by expensive its that the cpu is a burn once and the board doesnt support a reburnable chip so you have to make the ecu boot from some other cpu on an expansion board (im pretty sure thats right) and then burn once a map.
in the case of the r33 its just easier and cheaper to get a powerfc. a remap for an r33 gtst could end up costing you 1200 odd easily. so its not worth it.
it doesnt matter what ecu you have, if you have motec, autronic, apexi, stocker, hell a nintendo gameboy. sure each has their own quirks and bugs and featureset but they all achieve the same goal. it really comes down to how well its tuned. if you were to compare a pfc tuned by XYZ workshop for $500 then compare it to an r32 remap by dr drift. if the remap has more load points adjusted (tuned) then it will be better, perform better and be a better car to drive. it all comes down to the tune. its fine to have XYZ ecu but if its not tuned accordingly then its pointless