Yes, I also found Yongle's abilities more fun than superb. You used his projects more than I did, though. I used Faith and Food in the early game to grab an early pantheon and build up my capital, but then it was the late game before I started using the Faith and Food projects intermittently between wonders and districts.
I don't think I used the faith project after the initial pantheon rush, and never used the gold project. I found with the food project, basically once I saw one of my cities was sort of in a "good shape" to rush to 10 pop, then I would run the food project. Basically if they got to like 7 pop, had 11 or 12 housing space available to them, then I would do the food project. On a decent city, they would grow every 3-4 turns I think. Basically spending 10 turns to rush a city from size 7 to size 10. And with Audience Chamber, it actually wasn't hard to get the housing - base housing + granary + AC bonus and you have unlimited space to grow. It's definitely one of the few games where my cities hardly ever ran out of district space (even had a Bi Sheng sitting around that I never used).
Now, obviously, a lot of my game got lucky, between terrain, nearby opponents, etc... I also had Hong Kong right next to me (other than a few turns where villainous Catherine captured it and I had to turn my attention to liberating it ASAP). I'm sure if their bonus was applied nicely to these projects, that could have made it even easier for me in my game. Also I did restart a few times until I had a "nice" capital, had a relatively easy Temple of Artemis build so that my capital got to size 10 fairly quickly.
But overall, I'd say they're certainly a very strong civ. Whether they're as "broken" as other civs when you play them to their best, I really have no idea. It was a really early win for me due to monopolies and the overall start. At least the fact that it takes a little effort for the abilities to kick in means it's not an auto-win - you can very easily lose the game before you hit 10 pop in any city. But I'd say it's definitely on the stronger end of abilities.