[michaelbuckbee]

Objectively better for SEO - and in particular if this isn’t a personal blog, but say a marketing site for your SAAS and then an accompanying blog. Having them in separate domains with very similar content hurts you

This has been fairly well beaten into the ground at this point.

[toddmorey]

I’d say objectively safer. Google is getting better at reconciling content split across subdomains as coming from a common source. Some Google experts have called it pretty much a solved problem, but I don’t think the data plays that out just yet. I do believe there will soon be a time that subdomain vs subfolder won’t matter for SEO. Just not quite there yet.