You are assuming the animation lock for one ogcd skills is = to a full gcd, it is not. I imagine with all the back and forth this subject has the dps is comparable in any situation so it really comes down to preference. I prefer to unload everything ogcd as soon as I get it to allow more chances for them to refresh. Some people prefer to have a more active system by covering their gcd, it is not that big of a deal. To me I like to empty out and have more time to be aware of what is going on.