I wrote a little scripts that shows [some stats about the frameworks](http://juliankrispel.github.io/css-specificity-benchmark/]
##Twitter Bootstrap Size: 16KB Bootstrap seems to be the default for many developers and startups. And I can see why. It has a boatload of fully designed, fully functional components (Not only CSS, also Javascript). It's biggest strength is however also its biggest weakness. Because Bootstrap is so fully featured and so 'designed' already, by picking it you are buying into their way of doing things. Although they vastly improved in their 3.0 release, Bootstrap still struggles with a high rate of specificity which make it hard to extend.
The new version of bootstrap has major advantages over 2.3.2. They shaved off 30% of it's codebase without feature-reduction and is 14% less specific than its predecessor.