Ask HN: SEO Question - Domain-Based Versus Path-Based Site Structure?

Over the last few weeks we’ve had a brewing debate over the best way to structure a new site we’re working on from an SEO perspective. Basically, we’re planning for the site to become very big over time and want to make sure our structure is giving us the biggest bang for our SEO buck. Below I have linked to a post on our blog that outlines a perspective from a key member of our the team. Clearly a more descriptive context as to what type of site we’re working on could be helpful, however my question to you is this: which structure - domain-based (topic.company.com), path-based (company.com/topic), or a hybrid - will deliver the most value from an SEO standpoint? If you have an opinion on the matter, we’d love it know it! Thanks! http://roachpost.com/2010/05/19/seo-question-domain-based-topic-company-com-versus-path-based-company-comtopic-site-structure/