Yes, Haste still makes a huge difference at max speed, but, to me the mechanics seemed to work a little differently than what the above people are describing. I did a battle with all characters at max speed and one character with the Angel's Tiara. What I experienced was that on the first turn of battle, all characters became "ready" at the exact same time, but on every turn after that, the one with the Tiara was always ready twice as fast.