Looks like 4.5 sec CD that always runs as long as you are less than 2 charges. This means you will have an extra chance at a proc every 4-5s no matter what's going on in combat. There are so many variables to consider to decide which is BEST, it's about as clear as mud.
Based on how rage is generated, It's hard to see a warrior is the superior healer anymore, especially with mana not being needed for the new CS. Rage generation seems too slow with a 2h to make for lots of proc chances on auto-attack and Slam. I notice though that rage is retained on any swing that is dodged parried, or missed, and you can keep spamming until it lands. Only then is the rage spent. I don't think this is the case with CS though. I remember misses and such on my old pally triggering a 4.5s ability cooldown. With procs only triggering when a hit lands, rage might be superior here since Slam is on a global.
In summary, the deficit for the warrior is in rage generation and the deficit for the Pally is in the CD. Hard to say who has the advantage. What du guys think?