It's extremely useful for kickstarting a project. I made a fully functional site in 5 hours using this. A process that would take at least 12 hours of painful css and javascript coding.
The documentation is very detailed too, which makes this even easier to use
Well worth a look if you're like me and hate doing designs from scratch
It's a flexible HTML, CSS and Javascript framework. You pretty much just download the library files and use the functions just as you would with jQuery and it does cool stuff.
I know you don't like jQuery. You really don't have to touch jQuery with bootstrap. You can do a lot of things without using it. The CSS part alone is quite overwhelming.
I'm pretty much just using the HTML and CSS templating functionalities. It makes it really easy to get a responsive design without the use of media queries etc.
Read through some of the docs and I'm sure you'll find at least one thing you'll like