I've shot them both ways and as far as wingshooting goes they both have some enjoyment. But as far the hunt, there is none in this sporting preserve situation. That's the point, they make sure you get on birds, in fact they ask how many you would like to "find" today before you go. By definition the word hunt is always hampered by that key ingredient to look for. If you take that out, yep it's downright killing.
A Pheasant Tower Shoot I filmed last winter.
http://www.americasoutdoorsman.com/backwood-ao.html
I have tetered on the edge of this one for a long time, I will admit. I can't stand high fencing native big game, but put and take fishing or wingshooting doesnt seem to bother me. Partially this is due to the fact that the impact is short lived and very few actually live through the first winter. None the less, its a hypocrites point of view.
I shoot quail regularly over pointers on a friends preserve.
http://www.americasoutdoorsman.com/doubleajan.html
Mostly boils down to sporting clays with feathers on them. Lots of shooting. While I shoot quail regularly 75% put out -25%wild, I have only shot pheasants once and I dont think I would do that again.

