I finally purchased a pair of 600EX-RT & one ST-E3 RT.
Moved from Phottix Odin, I must say that I'm somewhat a bit disappointed.
1. Lack of 2nd curtain sync.
My Phottix Odin can do this on any EX series flash. Why the hell ST-E3 RT can't even do this?
2. Lack of slave zoom control from ST-E3 RT.
Again, it is a feature that Phottix Odin can do.
3. Lack of USB port for potential firmware upgrade.
Look at Phottix Odin, they have numbers of improvements from their firmware upgrades.
Seriously if Canon can somehow implement a firmware upgrade on the ST-E3 RT & 600EX-RT to add those 2 above features (2nd curtain sync & slave zoom control), I'll gladly ditch my Phottix Odin completely & go for Canon.
Though, I'm glad I still have my Phottix Odin system. In the mean time, I'll continue keep using my Phottix Odin with 600EX-RT.