Take the day flight.
1) Full onboard service, and with >11 hours flight time you'll still have time to sleep, sample the bed and the PJ, etc
2) You can experience the lounge, you can get there at 7am if you like. It's definitely worthwhile experiencing. But I belong to those that feel that as good as it may be, it is still an airport lounge, so it will become boring after some time. My very personal choice would have been to get there by 8-8.15am, have breakfast and finish whatever you need to do online (because AF still cuts you off for >11 hours while you're in the air), and then board. If you are into massages (where you can ask yourself the question of whether you'd be having a massage at 8am in an airport because that is what you're into, or you do it because there is time to kill), then arrive at 7 or 7.30am
Enjoy!!