I think it is a good compromise between a stable and a field, the arrangement of the differing feeding, drinking and activity areas is meant to accord to horses' needs and allows them stay active at the same time. If you can have a more relaxed horse with this system, then I am 100% for it!
I have heard about it a few times already, but it is not very common in most countries 🙂
Horses live in liberty with different areas: rest area, roughage feeding area, feeding station for concentrates and minerals, water supply, paths with various round covering, play area...
It encourages many activities for the horses, in order to try to recreate what wild horses' life looks like. The horses soon become more well-balanced and work more efficiently because this system provide them environmental stimuli, fresh air and group life.
I think it might be a concept to explore more, but I am not sure it can be applied to every horses, in every countries and stables.