As no one has reported on mobility yet, i'd throught i'd give it a try. So using Visas (she's the only character who i could level up, in order to give her the feat) i ran a total of 6 times; 3 times without mobility, and 3 times with mobility. I started these runs from the left wall of the Khoonda building on Dantooine (the wall that has the large door), and ended all of the runs infront of the large pile of rocks between two trees, near the Crystal Cave. I ran in a staight line for each run and timed them using a stopwatch on my phone.
I found that, for the runs without mobility, i ran for 28.7, 28.9 and 28.6 seconds, on each run (an average of 28.73 seconds).
For the runs with mobility, i ran for 26.1, 26.3 and 26.2 seconds (an average of 26.2 seconds).
So using these averages, unless my maths is wrong, i found that i ran 8.8% faster with mobility, compared to without it.
The fact that i measured a difference in speed lower than 10% was probably due to human error with the stopwatch, hence the 8.8%.
Hope this helps you.