There are two reasons I wanted a movable tractor instead of a stationary run. One- Every stationary run I've visited was a barren ammonia pit. If I were a chicken I would want fresh grass and bugs to peck at.
Deep litter takes care of the barren ammonia pit.
I know quite a few people personally that have chickens, but have no idea how to properly care for them with housing and feeding. One person started feeding cracked corn only and asked me why his chickens aren't laying many eggs and why the egg shells are very thin or soft.
Almost forgot....My land is a mix of pretty flat mowed area around the house (2-3 acres) and bumpy overgrown pasture 50-100yrds away from the house (3 acres.) I'd rather the chickens be in the pasture but the thought of them being so far from the house scares me.
One thing to consider with location, are you going to want electric to your tractor or coop? Their water might freeze in the winter. We do get cold enough at times down here for that to happen.