Hi I've been looking about because I'm getting close myself, check out these threads:
UK boards - recharge time
US Boards 1
US Boards 2
I use it situationally. Soloing a big boss, taking on an AV, when the team suddenly aggros two groups and things start to go a bit wrong etc... I much prefer having it ready for when I do need it rather than get in trouble and find it's not recharged because I decided to use it in the easy fight just before.
You don't get rooted when you attack and you also seem able to pass through friend and foe alike so you can line up IS, run right through a mob and be well past him before the attack finishes hitting. Pop hasten and conserve energy (tho you probably don't need that with the built in end reduction) and you can rampage through pretty much anything but Psi mobs. 
Hi
I´m getting close to 38 now and planing to get Light Form. I would very much appreciate any tips and hints on how to best use it.