they are trying to sell us cheap technology with an absurd "premium". well, i don´t buy that anymore.
try some Yongnuo YN-622C or Phottix Odin stuff instead. both systems are very reliable.
Well, here the price difference between a 580EX2 last year and a 600EX-RT today is less then the price of an Odin rec. (The 430EX2 didn't change in price, just to rule out economical fluctuations). Also Canons solution offers Autoflash and five independent groups - w/o taking additional space or having more parts to take care of. The "ready"-confirmation on the transmitter is nice too.
Sure, 2nd curtain would be nice, as well as retaining the groupless slave mode or triggering studio strobes w/o having to rely on the sync port - but I tend to miss the RT-system when using the Nikons...