I'll be purchasing a new C'dale Evo within the next few weeks. Think I'm going with a Red setup versus Dura Ace simply because the Red will come with a 10 speed cassette and then I can swap all of my other wheelsets out on it. To me, it seems that the 10 speed cassette is optimal and I remember the debates held years ago when the jump from 9 speed to 10 was made. Any arguments to be made for adding another cog?