Originally Posted by
RiceisNice
It's 1.5 second cast on a 2.5 GCD, with the GCD starting when you begin a cast. That only leaves you with 1 second of of using oGCDs before your next weaponskill (which will be a cast unless you have a straighter shot proc) You can't use oGCDs during a cast. You can't immediately start a cast right after a oGCD due to animation locks, nor can you immediately do a oGCD right after an oGCD.
It doesn't weave well because you can't fit two oGCDs in the span of 1 second after a cast, not without it clipping into your next GCD by a split second to a second (which adds up in long fights).