I don't actually disagree with you on most points, but just out of curiosity why do you have the impression that Latex is slow? I used it to write my thesis (> 200 pages, full of images) and was re-rendering all the time, it only took a couple of seconds on my slow netbook.. When I'm working on a shorter paper, I barely notice the time between hitting "render" and seeing the result. (I realize I could even set it up to automatically render while I'm writing but prefer to concentrate purely on the text editor as much as possible and curb my urge to re-render constantly)