Even though the main use case for Bootstrap seems to be for rapid prototyping, any thoughts on using it for a production app (but perhaps custom-themed), instead of rolling a custom design altogether? It seems Bootstrap has matured to the level that it can be used as for most projects with little customizations if any. A lot of what I read in the comments imply that Bootstrap is great at prototyping an app and once that phase is over, you throw it all out and start developing a custom design based on what has been prototyped. Why can't one just stick with Bootstrap and customize it as needed?
I converted my Bootstrap 2 theme into a dark one: http://i.imgur.com/qm1iA.png
I call it... Darkstrap.