One of the most common questions asked by climbers moving to the Treemagineers Hitch Climber system, a friction saver or one of the pulley based rope savers ( ART and the Treemagineers) is: "Why should I invest in an expensive friction cord? My Standard-Prus works fine!"Transferred friction! That's why.
Running a climbing line over a branch splits the friction in the climbing system between the anchor point and the friction hitch.
When you use friction savers you still generate the same amount of friction (otherwise you wouldn't stop on the rope) its just that the friction is now concentrated at the hitch. The problem is exacerbated when you move to smaller diameter climbing lines and small diameter hitch cords.
The friction remains the same but the surface area to dissipate the heat is smaller. This heat will burn out a nylon-based prussic cord in no time.
That's where the 'expensive' friction cords come in. They are specially constructed from a mix of heat resistant Aramid (or Technora) and Polyester.
Ocean Polyester has a core of 100% Polyester. They all sport high melting points unlike nylon based Standard-Prus. You can extend the life of your prussic cord even further by tying a hitch with low 'base friction' eg Distel or VT (Valdotain Tresse).