During discussion with multiple manufacturers as well as overall study of the choke tube after market, they all try different scenarios of geometry, lengths of parallel, overall lengths, porting etc. A whole lot of hype in there for sure!!. They are mostly manufactured to better tolerances and mostly better than factory. I tested lots and sent lots back that proved nothing special. My study led me to believe that anything IC or more open shot about the same pattern unless defective or something so I was not interested in further study or purchase of open chokes. The longer chokes were better but to an extent and it depended on size of shot. The small shot patterns pretty good through most so differences are smaller. Things really change with the larger shot and all the different bore diameters.
Another thing I saw pretty consistent was that everyone is playing the same game as golf club manufacturers trying to out perform each other in that what was once XXX is now much tighter but labelled the same XXX. Almost all the after market mod chokes are more like IM or LF to add some shock and awe to how great it is. I've done a lot of patterning in my spare time. Lots to see there. At the end of the day, in clay target sports, your shooting a target at a somewhat defined distance with your various load and want to be confident things are about the best possible at that distance. Everything changes hunting as your now at a full distance range with applicable pros / cons.
I will say todays barrels with the lengthened forcing cones, overboring and whatever seem to pattern fantastic as compared to many of the mass produced barrels of the past. I also believe the aftermarket chokes are better than standard mass manufactures like Rem , Browning, Benelli, Beretta---- but, as mentioned above, in some scenarios not enough to matter and in others a very big difference.
JMHO