I just hit 50 on my Sage and am trying to improve my Telekinetics DPS rotation. The guides I've found all say only to use Telekinetic Throw when you get the Psychic Projection proc from Weaken Mind. But just from looking at the abilities, my TT does ~2800 damage over 3 seconds without a crit whereas Disturbance does ~1100 every GCD (1.5 seconds). So the DPS of TT is higher by about 200. If my buffs from Disturbance are up and I don't need to refresh them yet, why wouldn't I use TT over spamming Disturbance again?
In the end it seems this is due to the Tidal Force skill: Disturbance has a 30% chance to make Telekinetic Wave an instant cast, so the more you spam Disturbance the more you can use TW. Coupled with the Telekinetic Momentum skill (and, to a much lesser degree, Tremors) your DPS will definitely be higher if you save Telekinetic Throw for when Psychic Projection procs and use Disturbance as your filler move.
However, this works out to about a 2.5% increase in parses I've done; it's not the end of the world if you hit TT while PP is down.