Purchasing international stock or OTC F share equivalent?

I asked this question and got a great response by Flux, now I am faced with another dilemma:

Purchase the OTC F share or the "original" on the respective exchange?

My broker is Fidelity, and through international trading I can purchase UEX via UEX:CA or UEXCF.

Is there any reason to favor purchasing an OTC F share over international trading or vice versa?