I have the orthosport- I like it because it isnt bulky, especially if you are looking for something to barrel race in, and like I said it is super light weight! I feel like it is a pad to have if your saddle fits your horse well though. (if that makes since)
The Ortho Sport one is good, but I find it slips back on my horse the whole time, until the point where it has actually slipped right out while I was galloping uphill! But, it does help with the slim shoulders and a bit of a build up. I think I am going to try a build up pad for actual sway back or the circle y corrector pads next.