Currently Brunelleschi is partially responsive in the sense that it scales text and handles sidebar very well. But the post images are not being handled properly. Not sure if it is a problem with my site only as I specify width/height in the <img> tag. I have tested by re-sizing the browser window as well as viewing the site from phone browsers too [opera mini / android browser]. Fixing this one thing can make the theme "truly responsive" in my opinion.