My problems with the GCD aren't with the GCD itself....

I don't notice it playing melee classes or BRD--casters are where I feel the GCD most, and I think that was because of poor skill design. Really, just poor choices of what's on/off-GCD.

The advantage to an instant (burst damage) spell on GCD is the responsiveness--the damage happens at the start of the timer, rather than the end of a cast timer. However, several instant spells are damage/healing over time, for some reason (bio, aero, regen...), giving you the advantage of squeezing in, at most, an extra 1-2 ticks before the mob dies. Of course some spells (repose, fluid aura, ruin II) belong on the GCD, but I just feel like the devs didn't think this through.

The reason most of us feel the GCD most on WHM/SCH, I think, is because we've probably played a game where healers were all about reaction time. Mob uses <<MOVE>>, I'm used to having spells going to counter it before the animation is finished--well, sorry; the GCD has arrived! I'm also used to DDing a little while things are going smoothly, but I'm always prepared to interrupt and cure...but the 2.5 second GCD isn't interruptable like a 2.5 second cast time, making bio/aero more dangerous than aero II and bio II. Moreover, in some 4-man fights with sub-par DPS, I've had to stay curing constantly to make things keep going; there is no time to throw in those "instant" DoTs or even esuna, which has a low cast time but is still on-GCD.

Spacing between skills is fine, but some skills lose value when you can't use them for fear of locking yourself up for the next 2.5 seconds.