Ask HN: Bad idea to use something like Twitter Bootstrap in a production webapp?

I'm interning at a new startup, and I've been tasked with designing the front-end of the site.

I really, really want to use the new Twitter Bootstrap (http://twitter.github.com/bootstrap/). It's all CSS, looks amazing, works great, and lets me get to designing and not worrying about the little stuff.

However, is this a good idea if it's a demo of a webapp that we're building, that could become production code? Will it look silly and amateur if I use this instead of coding it all myself? Is the bootstrap too Twitter-ish for a real company's brand?

Thanks for any input you guys can give me.