You probably wouldn't notice an appreciable flow difference. But if the application absolutely needs the highest possible flowrate, then it may be worth it. The difference is that the hole in the barb section is drilled out slightly in the high flow unit and the walls of the barb are thinner.
If you really needed a flow rate greater than what a standard 1/2" barbed camlock can deliver, you'd be wise to upsize to 3/4" equipment.