I used to live in NH and have watched the (so called) hunters who follow the stocking trucks It's really sad what they do - and there isn't much left for others after they get through - they mostly have good dogs and are good shots. I liken them to the same mentality as the guys who follow the trout stocking trucks in the spring, and always catch their limits.
On the plus side - I have done a bit of preserve hunting in the past, and if you are careful and do your homework and pick the right one, it can be a very good experience with strong flying birds and good covers.
If you have the time and are interested in Grouse - there is a lot of public land to hunt in the Carroll county area - I used to live there and did a lot of hiking with my Golden Ret. and we almost always jumped birds along the trails on the flats and in the Sandwich mountains. There is a lot of cutting going on around there - making lots of good grouse cover.
Good luck