Yes, license is for the driver with driver version 2.x updates included. It is a separate Windows driver. The UrBackup client itself is unmodified (except the version number) from the installer found on the web site.
The performance difference is variable. E.g. on the example below it is smaller, because the PC has an SSD which can read all the 230GB of used space in about an hour. With CBT it (in this case) only needs to read 15.4GB which still more than halves the backup time and uses less CPU in that time.
So because it only reads (and hashes) 15.4GB it uses a lot less CPU (good for laptops on battery) and is faster. If you have a bigger volume or smaller changes it can have an even larger performance impact.
@TomTomGo
If it is active and the whole volume hasn’t been written to it will add a log line in the image backup log:
The CBT should take effect after a reboot and the second image backup after the reboot. If this does not show up I would of course be interested in solving this.