I really used to love Bourbon and Neat, but they're unnecessary today. The vendor prefix mixins are mostly obviated by modern tools like Autoprefixer, and Neat itself can be mostly reduced to a Sass mixin.
I second this recommendation, even for those not using Ruby! The Sass compiler is written in Ruby but that doesn't mean you have to know Ruby to use Sass.
If you can do without the latest of the latest in Sass I highly recommend using a libsass implementation. So much faster than the Ruby version!
OT: I also like that they've used a BEM-like approach, although I personally prefer a double underscore as separator between elements.
Libsass is night & day vs Ruby Sass. No problems using libsass with Bourbon, Bourbon thankfully stays away from the bleeding-edge features (many of which can be emulated with clever functions).
In a previous project, we saw Sass compiles go from ~15s to about 400ms by moving to libsass. Completely changes the development cycle (with HMR or livereload) as you see changes immediately.
I've been using node-sass (libsass wrapper) recently, which hasn't been too bad compared to less (which is native to node/js). Seems to be working fine with bootstrap-sass, and surprisingly fast, compared to less, so I imaging the ruby sass implementation would be similarly slow by comparison.
Just an FYI for anyone who sees this, you don't need to know or utilize Ruby at all in your workflow to make use of SASS/Bourbon (not sure about Neat, but I'm guessing it's like Bourbon?). You just need to have it installed and be able to install a few gems (gem install gemname) and you're pretty much good to go. Or there are a few GUI options out there that make it even easier.
I couldn't write a damn thing in Ruby and I utilize it every day via SASS/Compass