I have a customer that is needing new hardware and we are thinking of upgrading their software too. Is it better to a new install or to migrate?
Even with the new build of CCM 6.x on a new box you can choose the Windows Migration option using the Data Migration Assistant (DMA). Just run the DMA on the old CCM 4.1(3) before you start and it will produce a .tar file that can be used to move the data across to the new version;
Import Windows Data
This option allows you to import database information from a Cisco Unified Communications Manager 4.x system by using a file that the Data Migration Assistant (DMA) tool produces.
Upgrading the First Cisco Unified Communications Manager Node
When you choose Windows Upgrade, the installation wizard prompts you for the location of the preexisting Windows configuration information that the Data Migration Assistant (DMA) tool created. See the Data Migration Assistant User Guide for more information on the DMA tool.
Step 1 - In the Windows Upgrade window, import data from a Windows version of Cisco Unified Communications Manager by choosing Yes
Hope this helps!