I have one, and I use mine every cook. The dad cooks dinner guy blogged on the weber nation site about rotisserie set ups, and mentioned again he doesn't always use it.
I figure it came with it, and if it will reduce strain on the motor and make it last a little longer, why not. It's not that hard to put on.
Welcome! Whichever way you go post up some pictures. Welcome to club from "one of the spinning people"