I am running a campy ergopower shifter (10s) with a shimano 9s cassette. I have been doing this for a while but recently got a new wheelset (AC 420). So I am getting a new cassette to go with this wheelset. My question is about hte Dura Ace 9s cassette. I am wondering whether to go exotic and look for a DA or token 9s cassettee (fairly cheap, lessthan 100). Those cassettes are made of exotics materials such as Ti and Alu, so they may not last as long. My question is the longevity of cassettes. SHould i go for a regular ultergra or SRAM 9s cassette (steel) or something more exotic? In your experience what is the diff in longevity. I am around 1120-30 lbs and commute (sometimes on my race bike) and race in local criteriums.