VMware vSphere 5.5 has been released on November 2013 and contains some improvement compared to previous version . If you wish to try to implement VMware vSphere version 5.5, these are some precautions especially for vSphere free edition.
vSphere Client Version Windows
vSphere Client version 5.5 cannot be installed on Windows XP or Windows 2003 32 bit. Windows XP 64 bit or Windows 2003 64 bit would be OK by using the following workaround : vSphere Client and vSphere POwerCLI may fail to connect to vCenter Server 5.5 due to a handshake failure (2049143).
Suggestion : It would be better to use Windows 7 or Windows 8 if you want to keep using Windows based vSphere Client. Alternatively, use the vSphere Web Client which can be accessed from browser on a Windows operating system, Linux or Mac. vSphere Web Client requires vCenter Server.
Virtual Hardware Version 10.
Beware when choosing a virtual hardware while creating virtual machine. vSphere 5.5 using virtual hardware version 10 (that have compatibility with vSphere 5.5 and the next latest version) by default and VM cannot be edited setting using the Windows based vSphere Client. Edit Settings can only be use by using vSphere Web Client that will require vCenter Server. Instead, select Virtual Hardware version 9 which has compatibility with vSphere 5.1 and above or Virtual Hardware version 8 which has compatibility with vSphere 5.0 and above.
vSphere Web Client
Most of the functions and new features of vSphere management will only be available on vSphere Web Client . Only a small portion of the functional feature using vSphere Client based Windows, for example : vSphere Update Manager (VUM) and vCenter Site Recovery Manager (SRM).
Enhanced vMotion Features
Enhanced vMotion features (VM migration for host and data store when VM in active/powered on) can only be use on vSphere Web Client; the features itself will be disabled on Windows based vSphere client.
vCenter Server Appliance 5.5
vCenter Server Appliance (vCSA) version 5.5 using vPostgres database and has many improvements regarding maximum capability. According to some sources, vCSA 5.5 can be used to manage up to 300 host server and up to 3000 VM. The increasing capability of vCSA makes it an attractive option against Windows based vCenter Server (in terms of licensing costs and management simplicity).
VMware vSphere Data Protection
VDP version 5.1 does not contain compatibility matrix support for vSphere 5.5. It’s highly recommended to perform upgrades into version 5.5 or simply deploy new VDP version 5.5
If you want to use vSphere Replication (VR) 5.5, perform host and vCenter upgrade to version 5.5 to prevent any problem regarding data integrity. Read the following article “Updated: What you need to know before upgrading to vSphere Replication on 5.5” for more information.