I thought Form Shift was suppose to be this awesome ability to help us keep GL up? Well it doesn't really help. It has worked for me like once during some of the new boss fights. I use it all the time to start, before engaging an enemy.
Anyone else feel like its a waste during a fight? I feel like the level 60 ability should have been something to convert Chakra to a stack of GL.
I think the idea is that if you're forced out of melee range for several seconds, you can resume the fight in your third stance and refresh GL immediately, rather than having to spend ~4 seconds working your way through your first and second stance. GL lasts for 12s, so this gives you ~33% more time to recover.
Form Shift is by far my absolute, most-favorite skill so far, and I'm still experimenting with it. I use it at the start of a fight once so I can open with a debuff-inducing Dragon Kick, then go into the PB rotation which we now have an extra attack on since we don't need to apply DK during PB.
I personally don't see the point in starting with Demolish because it will be applied without the TS buff, whereas Form Shift, DK, Twin, Demo is a great buff/debuff/dot setup, then you break straight into the hard hitting abilities. Then again I don't crunch numbers and am still experimenting so maybe starting with Demolish is better - but for me starting with the debuffing Dragon Kick seems better and also doesn't have us shifting forms repeatedly before a fight
Where this skill mostly shines though is during boss fights, and I tell you the use of this ability has massively increased my GL3 uptime. For instance; if a boss forces you out of melee for a mechanic then Form Shift while moving to put yourself in Coeurl Form then shoulder tackle back in and throw up demo/snap to keep your stacks up. This ability, added with the fact that GL is applied instantly now, has kept my GL3 up in circumstances where previously it would have fallen off. You just need to always be on your toes and know what form you're in during the mechanic so you can land yourself in Raptor / Coeurl Form for your return.
Finally, for bosses that disappear for an extended time and reappear ready to hit with some hard magic attack (Bahamut style), form shift in preparation and Dragon Kick them in the face - they do less damage.
tldr: I want to marry this ability.