Yeah... My personal experience with Bootstrap is somebody built a site using their grid system that I took over. My boss wanted to add a bar across the top but because all elements had class names corresponding to their position ("row1" etc.) the only way to do that was to rename every single HTML element. This would have been a two minute fix using vanilla CSS. If I had all the time back I spent resetting line-heights bulldozed by Bootstrap CSS I could have built an entire new site.