vMotion Between Hosts With Differing CPU Versions

After setting up two new ESXi 5.1 hosts in a cluster I found that I was unable to vMotion between them as the CPUs, whilst both Intel Xeons, were different versions. The error I received was;

The virtual machine requires hardware features that are unsupported or disabled on the target host (SSE4.1)

To make this work I had to follow the steps below (as advised by VMware) and enable EVC on a Host Cluster;

1. Connect to the vCenter Server using the VMware Infrastructure (VI) Client or vSphere Client.
2. Create a new empty cluster which does not contain any ESX hosts.
3. Enable EVC on this new empty cluster. Choose the CPU type (Intel or AMD) and the chip generation.
4. Migrate all virtual machines off of one ESX host in the existing cluster.
5. Put the host into Maintenance Mode then drag and drop the ESX host into the EVC cluster. Exit Maintenance Mode.
6. Using the VI Client or vSphere Client, directly connect to the ESX host which is hosting the vCenter Server virtual machine.
7. Right-click the vCenter Server virtual machine and click Edit Settings. Click the Options tab then General Options.
8. Note the location and name of the virtual machine configuration file (.vmx) on the datastore.
9. Power off the vCenter Server virtual machine.
10. Right-click the vCenter Server virtual machine and click Remove from Inventory.
11. Using the vSphere Client, connect directly to the ESX host which is in the EVC cluster.
12. Browse the datastore which contains the virtual machine configuration file for the vCenter Server virtual machine (as noted in step 13 above). Right-click on the virtual machine configuration file and click Add to Inventory.
13. Power on the vCenter Server virtual machine.
14. Using the VI Client or vSphere Client, connect to the vCenter Server.
15. Right-click the ESX host not in the EVC cluster and click Disconnect to disconnect it from the vCenter Server Inventory.
16. Drag and drop the disconnected ESX host into the EVC cluster.
17. Right-click the ESX host and click Connect to connect it to the vCenter Server Inventory.
18. Repeat steps for each ESX host in turn until all ESX hosts are part of the EVC cluster.
19. To confirm vMotion is now working, try to vMotion again between hosts.