Selected answers from the Dumb SEO Questions Facebook & G+ community.
Dave Elliott: yes, slash matters......Or it as the case is
Richard Hearne: No, slash doesn`t matter in the case of root domain. It does matter for any inner resource on a domain, but not the root page.
See: https://tools.ietf.org/html/rfc2616#section-3.2.3
An empty abs_path is equivalent to an abs_path of "/".
Dave Elliott: Hmmm I stand corrected. Never knew that!
Faith Dugan: i dont understand this "canonical" thing and when to use it...