CMS wise for CB nothing has changed. So simply phpmyadmin export and import would work just fine. Do not do this for your users however. You should migrate your users using CB Juice so their user_ids are correctly generated. Basically export everything and import everything then empty the _comprofiler table. Using CB Juice export your users then import your users and you should have a safely migrated CB site. Of course there is no guarantee of this and I do not recommend you moving to Joomla 1.6 as it's basically a "bug nest" so to speak riddled with issues that other developers (including us) as still trying to address.