Do you really need your mount button in the middle of your screen? Overall, too much stacked up in the middle, blocking your view of your character while leaving the corners (where nothing important is ever shown) empty and useless.
Like I said, work in progress. The bottom right corner is actually where Grid is placed.
Do I need the mount button front and center? Not really. Do I really need to change the UI at all? Not really. It's just convenient. That bar used to change when in combat, and while I dropped that, I grew accustomed to having it there.