toferjThe S straps work best on almost all women, and men with athletic builds, surfers, climbers, swimmers etc, men with average builds usually find the J straps work better
toferjThe difference is primarily in size. The larger, Catalyst = more stuff = heavier load = has a different support structure/frame. It has an additional foam pad, with two aluminum stays sewn into it, to provide the additional support.
(It took me a lot of energy to finally find a picture of the different support system, but alas it is tucked away on a private forum, and I do not have ownership of that content.)
I will soon have both the Catalyst from this drop, and the Circuit from a previous drop. Should anyone have any questions, want any pictures.
toferjThe internet is a marvelous thing: http://www.ula-equipment.com/category_s/1836.htm (the only difference is that these packs are made from Cuben Fiber vs. Robic Fabric, making them lighter and more water resistant).
(It took me a lot of energy to finally find a picture of the different support system, but alas it is tucked away on a private forum, and I do not have ownership of that content.)
I will soon have both the Catalyst from this drop, and the Circuit from a previous drop. Should anyone have any questions, want any pictures.