Thanks a lot for the replies all!
From what everyone has said I'm definately sold on not going to 4.10. I think I'll go with the 3.91 unless a really good bargain comes around on the 3.55.
I'm in the process of a tire switch (I have no traction with the current tires, they are too hard), so I'll make sure I get taller tires if I go with the 3.91 route.
Thanks again!
