I know of one chap that has both cars up and running and has ran both back to back.
I asked him recently what he thought as I'm looking at buying a C4.1 myself for the 2012 season - his response was that the C4.1 was a improvement over the old Atomic Carbon S2 and generated more rear traction than the old S2. He said that the Durango was probably a better choice for the 'average' club driver as he felt it easier to drive and a little bit more forgiving. But said that the C4.1 was faster, and a good driver would definitely get more out of the C4.1 than the Durango.
It certainly helped me make my mind up... C4.1 on order come payday
