I'm not familiar with either of those Generics. But, I can say throughout my time spent in different countries, both Eastern and Western (that's where you pick up the subtle stuff about 'x' brand/generics) it's mostly just the quality or what they use as the binder, and whether or not it states Instant Release or Sustained Release. The two have MUCH different effects.
I gather you're wise to this already, yeh? I use 100mg generic Indonesian Trams that are SR as fuck. If you do come across SR's - just swallow them, chewing, dissolving or crushing will negate the 'desired' effect in the long run.
As far as a direct answer goes, well, shit, if the same dosage of 'x' taken in the same mental/physical state as 'y' - then just keep researchin' or ride the placebo, yo.