What's the benefit of Latex over LyX? With LyX you can insert latex if you need it, but otherwise you are in a very nice Wysiwym environment
Lyx is great for shorter things. I use it for presentations, where being able to see the images, colors, etc really helps.
For longer stuff, with a lot of text, a nice editor has its advantages. And you can split of chapters in extra files easily and all that.