I personally think it's better to have too much range than not enough. That's why I'm still trying to increase my pup's natural range with little, if any pressure, so my preferred distance right now is however big she wants to run. There's an old saw about "you can always take it out, but you can't put it in" when it comes to a bird dog's desire and range, meaning you can always shorten up a big-running dog through training but it's very hard to do the opposite. I'm hunting my pup this first year primarily in open areas that give her a chance to stretch it out while still maintaining some semblance of line of sight between the dog and myself. At this point I'm more concerned with boldness and confidence than manners, and if she wants to get out there a few hundred yards and really open up her throttle, all the better. As long as she checks in with me while hunting and comes back on "here" and a whistle tweet I'm happy regardless of how far out she gets.