I've started playing him, and he's the first leader I've given much time to who has the spiritual trait.
It's nice. I'd estimate that even without abusing it to flip civics to whip/draft armies it's awesomely powerful.
Ask yourself this question? How many times have you wished you were just a couple turns faster on getting something done? Be it racing for a key wonder, or a key tech. If you are playing spiritual, you probably save 10ish turns over the course of a normal game, and even more over the course of epic/marathon games. More if you switch civics a lot, less if you have BTS and only switch civics during a golden age or when you have no other option.
-Sinc