As far as our research & experience tells us, neither is more important.
Content IS King! For business owners, content is the most important aspect of any web site and its online presence. Your visitors come for the content, and they stay for the content, and it is the content that causes conversions, especially eCommerce websites. If your content is well organised, properly marked up, easy to navigate and “ranks well” on Google, you have good SEO (search engine optimisation).
You can’t have good SEO without good content.
However remember that custom website design is content. If your web design supports and emphasises the content, making the information visitors are seeking easy to find and understand, then the design is effective and is a positive aspect of the website. If the website development & design is clunky, cryptic and confusing, with a lot of razzle & dazzle, then the responsive web design is absolutely more important than the content – however the impact would be negative.
Do not let the design get in the way of the content or think that the design is somehow separate from the content. All is one for the user experience. That’s what we bring to the table, expert knowledge, years of successful experience & customer support. Try us out.