Ok let's clear this up real quick. In general sintered > extruded. But there are many types of sintered base materials and same with extruded. For instance the base on my Nitro TG and some older Gnu/Libs were not sintered, but I swear they felt just as fast as any other sintered boards I've owned. For me, I can't deal with a slow base. I'm constantly traversing, riding heavy NW pow, and also finding myself on flat cat tracks getting back to lifts or flat ares in the slackcountry trying to get back out. A slow base would be a killer in my world. If you live on the East Coast or SoCal or just ride groomers, then yeah who cares.
16 Gnu Swallow Tail Carver . 16 NS West . 15 NS Snowtrooper BIA
15 Now Drive . 14 Burton Genesis
14 Flow Hylite