LyX has a really nice online math type setting system. I have a math heavy document that I wanted to type up using LyX. Pretty soon I had the classic problem of any feedback system with feedback delay - oscillations. I would type something, it would take about a quarter of a second to update, I would move my mouse to click on a formula, it would take a quarter of a second to change state and by that time I would have clicked twice, the document would have scrolled, and the formula would change state again, because I had clicked somewhere else.
Welp. Its back to good old latex and text editors for me. I don't mind the write-compile cycle.
LyX is good for text documents, but for math, at least on mac, it is so sluggish, it is more annoying than anything.
I have found texmaker to be a very nice IDE on mac.