Are you using Twitter Bootstrap to create websites? Please elaborate.
No, I don't. I prefer to use my own code. But if it makes you more productive, go for it.
I use it a lot with landing pages. I work a lot with automation so emails and landing pages and when I need to turn out responsive designs quickly I go for it.
You can try the DMXzone Bootstrap extension for Dreamweaver. It has a great integration in design view and you can create responsive layouts pretty easy. Oh, yes it's also free of charge, all you need to do is download and install it in DW.