One reason that I like this particular model is that the hooks swivel and lay flat if bumped. Since mine are hanging in the barn aisle-way, I have to be especially cautious as fractious horses make their way down the aisle, and a fixed-hook hanging at eye level is a disaster waiting to happen. Unfortunately, not all of our boarders are as concerned with safety as I am so there are some tack racks that hook over the top of the feeders that don't have the same safety features as the model that I prefer.
With the portable tack rack I now have room for my riding tack: bridle, helmet, breast collar, and crupper.
By the way, I love this purple one as it is brightly colored and much easier to see than the black ones. I wish I'd bought more when I got this one!
Many endurance riders have a tack rack hanging on the other side of the wall, which would be the entrance of the trailer. They hang their rakes and blankets there. I was always hesitant to store rakes and tack in the horse compartment as that just seemed too risky for my comfort level. But for camping, it would be a great way to store blankets when the horses are not in the trailer.