I'm quickly discovering that, as I reach higher levels and have more energy, meditation is quickly becoming pretty useless. If I have to focus-meditate 30 or 40 times at level 20 in order to refill my energy bar... that's 15 or 20 minutes of cooling down.
I'm not sure how you'd want to balance it, but I would be much happier with my investment in Meditative Arts if meditation returned a variable % of energy, instead of a fixed % (max return being 10% instead of 24 energy? Something like that?). That way you can reach the energy return cap after many fewer meditations, and feel like the skill is actually worth having at higher levels.