Kinda neat, I don't see yet any added benefit over Bootstrap however - the problem it solves in a visual way is not really a problem for a mildly experience web developer and for the beginners it's not enough functionality IMO. As a thought experiment it's cool, as a viable product it would need some work.
Thanks for the feedback, PageBlox is not meant to be a tool for professional or even novice web developers. It allows someone who has no experience with html/css to create a functioning cross-browser compatible layout and build on top of that with their own css, which is trivial to learn.
I don't think someone that has "no experience with html/css" would care or understand what a "functioning cross-browser compatible layout" is. Just my opinion though, I've been wrong before!