I was always in favor of an approach where anima charges faster when you have a low amount, and charges slower when your current total was high. A deceleration in the rate of change occurs as you build anima.

I thought it was nice in that you still had a limit on how much you could teleport around but it wouldnt be as bad when you were empty. logging out to go to sleep/work would give you more this way if you used a lot the night before.