Hi, <br /><br />I'm planning to get a new wheelset, currently using Mavic Comsic (about 6 years old) but it's going to be retired soon. I'm riding a GIANT TCR ONCE Replica 01 model.<br /><br />1. Mavic Ksyrium<br />2. Mavic Comsic<br />3. Shimano WHD6xx/7xx<br /><br />Need advice on the diff b/n 1 & 2 and 1&3. My budget is around US600, don't think I can get 1 or 3 w/7xx. But I may be able to get it elsewhere. I want a more responsive wheel especially on the climb, not so much on sprinting though.<br /><br />Also currently with Shimano 105 cassette (9speed), is it ok if I use DA's 9 speed cassette on the new wheels but with the current 105 groupset?? <br />Any comments/advice greatly appreciated.<br />