Pros: Icetech and Freeza technology seem to help control overheating and brake fade over regular rotors, they look kinda awesome too.
Cons: Not the lightest (115g for the rotor w/o 10g lockring) compared to other Centerlock rotors, seems to wear out quite a bit faster than RT86 or other Icetech rotors, Centerlock only compatibility greatly limits wheelhub options.
I've gone through a number of the RT99 rotors (180mm front, 160 rear) and they perform great. On long decents I used to experience brake fade / overheating / pump much sooner with non Icetech rotors. Since switching to Icetech and Freeza I've noticed much more consistent braking performance on long descents. This might also be due to the finned Resin brake pads I was also using. Also, it's hard to quantify how much of a difference the Freeza cooling fins provide over non Freeza rotors.
I actually prefer running Centerlock hubs because they tend to be lighter than their 6 bolt counterparts and the locking interface is so much easier to use (w/ tools you probably already own) than dealing with 6 separate bolts.
Regarding wear - I've been able to squeeze out something like 1700 miles out of the Shimano RT86 Icetech rotor vs. 1100 miles out of a Shimano RT99, both on the same bike setup as a rear rotor with same brake pad compound (resin), using different wheels. I've also experienced a bit of delamination of the steel braking surface and the aluminum core towards the end of it's life - something I never really experienced with the RT86 rotors.