Posted 20 June 2013 - 04:33 AM
Dynamic updates: Murder of Crows, Barrage, Dire Beast, Stampede, Pet Attacks/Abilities
On Hit/Application Snapshots: Serpent Sting, Glaive Toss, Cobra Shot, Explosive Shot, Lynx Rush, etc.
Most shots are instant (e.g., Serpent Sting, Arcane, etc.) so the subtle difference between on use and on hit/application is misleading. When Cobra Shot hits, for instance, Serpent Sting is then refreshed at your current agility stat level. Glaive Toss is also on hit, and this shot has to travel. In general, the differences here are not worth saving a glaive toss or something like that for, but you asked.
Survival is the spec that can really benefit from timing and understanding the snapshotting process. With Renataki's and Bad Juju, it's best to refresh serpent sting, via Cobra Shot or a new Serpent Sting, right as the overlap is ending and then use Fervor to regen focus for a bit. This is especially true on multi-target fights where Serpent Spring can be hitting for 3-6x it's normal damage if you can refresh properly.