I guess I havent really had issues with mobility/movement in a tree stand. I dont use small stands, I used to build my own hang on stands and later ladder stands with large platforms. That helped a lot with comfortable movement as well as good back ground cover. You have to pay attention to what you and your stand are going to look like from a deers perspective, too many stands get hung in the wrong place due to the ease of hanging them not the advantage the location offers in terms of cover. Also keeping your stand quiet is as important as keeping your bow quiet, probably even more important really.
Practice from your stand and make sure it all comes together before the season and let the deer tell you when its OK to move and you shouldnt have much in the way of problems.