If they are both made correctly, I would hazard that it would be difficult to tell the differenece in the patterning...
One thing I will say about after-market chokes (and factory chokes for that matter), is that they are very often made incorrectly...
I have ordered chokes for wing-shooting and clays from a number of different companies, as well as measured factory chokes that were not made with the correct constriction.
I check all my chokes (after-market or factory) with a bore gauge... When ordering chokes, I always let them know I will be checking with a gauge... I have sent many, many chokes back that were incorrect.
That being said, for my last gun I ordered Trulock, and they claim a tolerance of .002, and all of the chokes they sent me were spot on for constriction.
I will add for those looking for a new choke, that from my research, I would stay away from ported chokes...