Burning speed will depend for the most part on the drive andthe disks you use rahter than the software.
If you have version 6 of Nero you will be burning as fast as is possible with it as it is now.
Updates are available free of charge from ahead.com
Upgrades (to other versions) have to be purchased. Be aware though that updates are up to 35mb each.
Post details of what you have at the moment and what problems (if any) you are experiencing.