subdomain vs. domain

The advantage of sites with full domain name over sites that use subdomain is obvious.
For web spiders main page from http://rumburak.hostsite.com is treated as a subpage of domain which homepage is http://hostsite.com , so has lower position from that it could have if it would be a separate domain http://rumburak.com.
Now subdomain is treated as a subpage of a domain, thus subdomain is as strong as the main site, that could be bad if the domain hosts other vicious subdomains affecting overall ranking results.
On the other hand, one positive thing is the age of domain.
When you introduce a brand new domain say , rumburak.com it takes some time when it will be recognized by main SE. Search engines like old, mature domains and tend to rank them higher.
When you create new subdomain rumburak.hostsite.com it gets the age from the host, and is treated by SE like the old domain.