well I can only speak from my own experience.
I have only one .cc : factoring.cc
its a dictionary word : http://en.wikipedia.org/wiki/Factoring_(finance)
with following informations : (from estibot)
Domain: factoring.cc
Keywords (Autodetected) factoring
Frequency (Google) 18200000
in Anchor Text 150000
in Title 301000
in URL 135000
PPC Ads Score 93
Overture/mo 81276
Wordtracker/day 525
I have tried to sell it for around 3000$, but I have not gotten any offers yet
So apart from this one, I wont buy/reg any .cc anymore
From now on I will only buy .com.
.net and .org only if its veeeeery good
I hope you can use this for something
Best regards...