For leveling, higher utility will speed leveling. Mags and lock both provide quicker trips to the trainer and back to the leveling area. Mage can port characters where they need to go, and they can hearth back to near the leveling area. Locks are better in that you can hearth (2 at a time) to the trainer, and summon right back to where leveling, including inside instance. Aside from trainers, quick travel between vendors and back even is handy.

Travel time is not small and should not be underestimated for leveling