I've been using LyX since ~2004 or so (version 1.3.x maybe?). I've written several papers, my master's and PhD theses, brief reports, software documentation, and many grant proposals with it. Over that time the evolution has been steady and quite impressive. The new features are useful and mostly unobtrusive (though I'm still figuring out the 2.0 icon artwork!). The changes serve a purpose instead of being change for change's sake. LyX today still has the same feel as it did back then, but so many things just seem to work better now. When I consider software evolution in general, and open source software evolution in particular, I think of LyX as a great example to follow.
So, thanks, and keep up the great work! Derek