I love this theme. It's simple and clean. It's exactly what I need. BUT. I noticed that bootstrap.min.css comes in at about 121kb, and I think with every feature enabled you only need ~16kb of that 121kb CSS.
I ran Grunt-Uncss over my WordPress site using Sparkling and got it down to ~12k (Not using the slider). Here is a link to my site: http://willrees.com and here is a link to the css file: http://willrees.com/wp-content/themes/sparkling/inc/css/bootstrap.min.css?ver=3.9.1.
It might be worth including the optimized bootstrap file with your theme. Makes it even snappier!