Used to keep them on as i liked the visuals. But it distracts me, as they are at the same position as my real hands and wheel, so it feels odd. I run single screen, with very low fov so it feels more real to just see my own hands.
Depends on whether I play on the Rift or my monitor. On Rift I use wheel on, and arms sometimes (not sure with R3E as I haven't got it running well with the Rift yet), depending on the game and it's arm animations.
When playing on a monitor I turn both off, I already have arms and a wheel, no need to see a virtual one.