Here's the deal as I see it w/ the ksyrium elites. They look badass, no doubt about it. They are stiff (for me, although I am very light) and durable. They seem to roll well (I have no experience w/ better wheelsets though), and as a whole I really enjoy my set. However, in hindsight, I'm not sure if I would repeat the purchase. If I had $650 to spend on wheels (retail for ksyrium elites), I would scour ebay, the bf road bike marketplace, for sale section on weightweenies.starbike and slowtwitch.com for a good used set of Ksyrium Sl wheels. They will be lighter, more durable and higher quality. Alternatively, I would get a custom set from psimet or someone similar.
That being said, you won't be disappointed w/ the elites. Mine have been great so far. But, there is nothing glaringly awesome about them.
Also, check out the new dura ace clincher wheels, they are pretty bad asss