New Canon 5D II - what lens for lanscape?

Hi everyone, I finally got tired of waiting for a potential 5D III and bought myself a 5Dii with the 24-105mm "kit" lens. I haven't had a chance to play much with it (only indoor shots so far).

Here's my question: I bought the 5Dii specifically to take the best landscape shots I can. I sold my 7D + 17-55 + 10-22 to get the 5Dii. Since I would be shooting mostly stopped down, at ISO 100, on a tripod, would I see an advantage in the 16-35 f2.8 over the 17-40 f4? Does anyone here happen to own both these lenses and a 5Dii? Also, what is the "sweet spot" aperture for either of these lenses?

Thanks!