Thanks for that. Just been playing the first 150 turns of a game with +1 food agriculture, and WHAT AN IMPROVEMENT! Gameplay is just so much smoother, it's unbelievable. It takes a little bit of time to actually reach happy caps, you need more than just one or two farms to supply the whole city, so much of the tedious micromanagement is gone, you can't just automatically race to huge happy heights when you get a religion, cottages are much more viable vs elder councils, and food resources are actually useful!
Settlers and workers are still very cheap, but they take enough extra time that it detracts from other production, and so REXing is significantly reduced (even by the AI). As a result, there's more unsettled land, barbarians are a bigger threat (and for much longer), and it's not just a race to pop out the most settlers possible.
Right now, I am absolutely loving the difference it makes. I still feel as though I would probably stick to it as the default option (at least until sanitation), but that's something that could be helped by beefing up the other civics. And it would be nice to try moving it back a tech or two (not sure where I'd move it to though), or giving it some associated penalty. But it improves the flow of the early game so much that I'm convinced that the reduction in food bonus is a very good thing.