I have had my barefoot saddle for a few weeks now - took a bit of getting used to but I love it and my horsey seems to prefer it too.
and as it moulds to the horse's back it doesn't slip and therefore his girth doesn't have to be done up so tight - which is good for him as he seems to have belly issues with being touched around there, but is much better now.
it is similar to riding bareback, but you have more support with stirrups etc - rising trot took a bit of getting used to but I am much better at it now and canter is really comfy!
I have been riding in treeless saddles for several years. I have a Torsion which I prefer to the Barefoot, but that is just personal preference. The most important thing about a treeless saddle is that you must use the correct pad underneath it.