Nice theme, but the css drop rules, if you change something in the portal_css grouping, can lead to strange results.
I am just trying it on an homemade webserver before implementing on my site.
I find it is an actual improvement from the basic Sunburst Plone style, with improved functionality. Also the rendering on mobile devices even with 3" displays is great.
Still not sure how our theme will work for you? Head over to our Plone-demo website and give it a test drive.
Step-by-step installation is described in INSTALL.txt file in /docs folder. For general instructions read How to install diazo Plone Themes in Plone 4.x.