WRV Coils, 100x more durable then a firewire, and all the performance. If WRV wasn't an east coast shaper these things would be blowing up.
I was sketchy on my purchase, but after a good 10 sessions i swear by it. You can feel the flex off the bottom, and this thing has taken some closeout beatings and guaranteed sand burys without a spot on it.
Anyways check them out, best performing non-poly board on the market, minus firewire, but i've heard too many horror stories about them breaking for an 800 board. Coils only set you back an extra 100 over tradional shapes.
epoxy is just a resin, just a way to saturate fiberglass onto the foam of your choice. epoxy is a way better way to go if you want a board to last and be safe for the environment. as for firewires the only thing that i do not like about them u get a rail ding and the balsa rail is compromised your flex patterns are ruined, and creates a very weak spot for another more catastrofic break. in poly or epoxy rail damage can be an easy fix if done by the correct person.