10% is really great. I just tested it and 12 hours overnight it took almost 50% :\ which kinda makes me sad, as I always told people that one of the big + about Macs is their battery life, but these new unibodies are kinda failing in that 🙁 I'll go to an Apple store and ask if that is normal.
BTW, my battery health is 100% after 7 cycles. My White MacBook after almost 500 cycles has about 85% health and lasts longer than this :\