It looks good on my iPhone. The elements are resized and centered.
Banner is at top.
You can simulate this by resizing your browser window. The page is not flowing properly when it is resized on my desktop browser. If you are detecting mobile devices and swapping style sheets, you do not have to do that with responsive design. You only need to detect the width of the display device. A true responsive design does not care what the device is.
I use Genesis Framework themes for WordPress responsive designs. You might want to take a look at the CSS code for some of those themes. They use separate blocks of CSS code for different display widths. There are demos on the StudioPress.com site.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin