Is fourwheeler.com wrong about the heat dissipating quality of higher volume remote reservoir shocks?
Your hose volume has to be less than the shaft displacement or a resi will do very little for heat transfer. The Bilstien 5160's resi's are right on the shock body so they do offer some extra heat shedding ability. If you have a 12" long resi hose on a 10" shock, it ain't going to do much.
resi's do offer more nitrogen volume and have less pressure change from heat than the Bilstiens with internal floating pistons.
Yeah, if you're nuking 5100's, go to a 2.5 or better. Big shock bodies gives more surface area to shed more heat, and more fluid, so it heats up slower.