I think there is a down side to country codes too.
.ru for example. It is the Russian country domain but 75% of spammers that I have blocked from my 5 domains have come from email addresses with the @mail.ru suffix.
Having domains that a lot of people are not familiar with can also result in mass blacklisting not only from webmasters, but also from email recipients.
I have 5 .org domains which are used for non profit purposes. I have recently registered a .cc domain for my own purposes for a tourism site.
I thought since it was free I would see how accurate my perception of these short domains can be. So many people I fear do not give them credibility.
With Respect,
Jim