Rode it for the first time yesterday. If you want to get from T4 - T3 and vice versa it's fine. However I needed to get from 4 to 2 parking so I took the train where it ends at 3. There is no escalator only an elevator to get to the "walkway". People were way backed up. Why didn't they extend the track to T2? Useless.
The walk is fairly long. Always a nice walk on a cool, August day in Phoenix