Love this theme, and so does my client.
We have been working to get it to look PERFECT on Mobile devices. After changing the header image to a graphic instead of text, we had difficulties getting the header to resize. Giving it percentages
(<img src="http://natbardonnet.com/site/wp-content/uploads/2013/12/natheader3.png" alt="Nat Bardonnet" style="max-width: 100%;height: auto"> <?php wp_head(); ?>)instead of fixed pixels seemed like it would do the trick, however it has a large space on the right hand side.
See picture for a clearer understanding: http://natbardonnet.com/site/wp-content/uploads/2013/12/download_20131209_135940.jpg