It DOES depend on what the scheme means.
To me:
"@" reads "at" and means, essentially, "belongs to" in a hierarchy, implying there is a M:1 relationship.
"/" is unpronounced, and means a subdivision (as per filesystem folder use), so implies 1:M relationship - a fan out.
Intuitively, I expect "user@domain" to be a proxy for a person. But "user@domain/resource" is something that person owns. Perhaps a software they've deployed? If that's the intent, then that seem intuitive to me.
Of course, I likely have computer/programmer brain, so IDK when it comes to the general public. 
Yeah that one to me seems most intuitive of these options, but far from great.
Unfortunately in the general public the @ has been rendered confused by the social media use of it.
Thanks, Twitter. :)
A new convention is needed.
