I dunno about stuns, except that they last long enough to be very obnoxious. Distract makes the player run the other direction if used correctly and on a runner. Very useful in Warsong Gulch. A much higher lvl player will see you easily in stealth if you are within a reasonable distance, and for the same level... you don't have too much to worry about, especially subtlety rogues.
Stuns last full duration, you can distract people. Stealth is impossible to see if you're behind them, if you're in front of them, the closer you are, the longer you're in one spot and the longer they're looking at the spot, the more likely you can be seen.