They might be different but the question is are they any better?
No choke manufacturer knows what ammo you are going to use and seeing that different ammo patterns differently through the same choke it becomes a bit of a minefield as to which is best.
If they said only use cartridge brand x with shot size y through this choke I would be a bit more of a believer that going aftermarket made an improvement.
I bought some Briley 1/4 chokes for my old Browning, I could not believe the kills, wow miles better... Or so I thought, when I measured them they were more akin a tight 3/8 constriction so I could have achieved the same result by buying a standard Browning 3/8 and it was just clever marketing. Tighten up the choke compared to a standard 1/4 and watch people be amazed at the breaks.
People also try to tell me the tolerances are better with aftermarket, however, the choke is based on the bore, if Beretta or Browning tolerances are so bad they cannot make a choke then how the heck will they get the bore right?
Also if the tolerances are all over the place what bore measurement do the aftermarket choke guys base their chokes on. They cannot increase the tolerances of their choke that much as they still have to accommodate the + or – tolerances of the gun maker.
There is not much you can do to a choke, it starts off at one measurement and tapers to another. You can play about with the length of the parallel section (or lack of it) and the length of the taper. I think most gun manufacturers over the years are not far off the mark now and without knowing your exact cartridge no one can say it's going to be better either.
You will find a cartridge choke combo that will suit you, it might be standard, it might be aftermarket but what I don't subscribe too is it will always be aftermarket that’s best.
Some aftermarket like Muller seem to have the hype and the confidence of their users sewn up, this placebo effect to confidence in shooting is definitely worth something to that individual but doesn’t necessarily mean that it’s a wonder choke that will benefit everyone.
Just My opinion for what it's worth.