Hi, The only thing I found on The Beta Test forum his the definition of license type. So, I buy the Floating license Today but did not get it yet. As a Beta tester the only license I test was node-locked on several PC (Farm). Maybe other guys have test-it. Anyway I'll post the link in the Beta forum.
License Type Definition.
node-locked means the license is locked to your computer.

floating means the license is locked to a computer acting as a license server, this server will be contacted by the plugin to retrieve a license. So you can have multiple computers with xStream plugins installed while only one at the same time can use xStream.

Meddo