Yes, there are some tunings on the defaults.
And it is recommended to install a fresh copy of 3.0 if it is not a big trouble to migrate your existing vhosts from 2.x.
I have a few vhosts (Rails VHOSTS using LSAPI) and see you recommend a clean install. What is the easiest way to move the vhosts over? Just copy their config files from the conf/ directory? Is there anything else I need to worry about regarding transferring to a clean install?
Yes, you can copy over the vhost configuration file, but not the httpd_config.xml, you need to manually add vhosts one by one or patch the httpd_config.xml manually.