Well, actually... I don't know if it's due to latency or their coding being similar to macro coding (no fractions of seconds for you! >:C), but I can activate CDs about a second or two before the ring vanishes. It's mostly noticeable through Brutal Swing, due to needing to time stuns on certain mobs' attacks. I've tried to check it via the tiny tiny countdown numbers (on dummies or otherwise "lazy" fights where I can take attention from the fight to actually look at the hotbars), and it seems that the counter reaches 0, and then the game goes, "Oh, this skill is ready now, I guess I'd better remove the overlay." Meaning there's a small delay between skill being ready and the cooldown overlay disappearing.
Admittedly, it's better to be able to activate a skill before it's "ready" than it is to think it's ready when it's not, and it's a lot better since they lowered the brightness a bit, but it's still annoying on those GCD cooldowns, since you pretty much know the rhythm of it by heart anyway. IMO, it'd be best if GCD overlays were in the old style, and only the longer cooldowns used the new style. Unfortunately, I rather guess their response to that request would be "PS3 limitations" =/
