I bought this saddle for a 4-year-old horse because of the ability to adjust the fit as he grows and changes shape, and it has fit him perfectly and has been fairly easy to adjust when needed (and it was also very comfortable for me as well which is a great bonus).
My boss at the time was very critical/doubtful of the saddle because of its adjustability and didn't believe it could truly fit a horse well; she asked me to fit the saddle to her most difficult-to-fit horse (she had spent upwards of NZD 20k on custom saddles to fit this horse and still had issues with the fit). The Arena Jump ended up fitting her horse perfectly and for the first time in a very long time, she was able to ride him with no issues and no extra raisers/padding besides a standard saddle pad.
I cannot speak highly enough of this saddle; it is great quality, perfectly lightweight, very comfortable for both rider and horse, the design is gorgeous, and the combination of leather on the outside and synthetic leather on the underside makes keeping it in great condition super easy! If I ever need to buy another saddle, I will buy Arena Saddles again no questions asked.