I feel 'meh' about it. I actually managed to win on my first play through on the 'normal' setting. As in no restarts for a better landing spot or reload because I did something stupid or got surprised in combat or something. I have been playing ever Civ since the original (including AC) and I never would have been able to do that with any of the others. The devs have said that at higher difficulty there is no different AI logic...
Satellites seemed interesting but not necessary, as was diplomacy. I didn't need any of the higher end techs other than to achieve my victory type. I only did a minimal number of quests.
It took me just under 400 turns / 11 hours to achieve the Harmony Trancendence victory. Last 100 turns / hour or two was waiting on stuff to be researched/built and waiting on the PC to take its turn.
Not saying it's bad, just that to me it has not lived up to my own excitement. Maybe I will feel different after some sleep and another play through. :-P