About the VMware Tools of ESXi 5.0 and why you should install them on vSphere 4.x

There is a rather new VMware KB article available that describes an interesting problem with the VMware Tools version of ESX(i) 4.1 Update 2: If the clock resolution of a Windows VM has been changed from the default then the VMware Tools service will continually consume 15% CPU performance (in a 1 vCPU VM, for 2 vCPU VMs it will be 7%, etc.).
We have seen this problem on few of our VMs, it looks like there are certain Windows applications around that change the clock resolution thus causing the problem. Detailed background information about the Windows clock resolution (and why it is not a good idea to change it) is available from Microsoft.

The resolution documented in the KB article is to downgrade the VMware Tools to an earlier version or - and this is probably surprising for most of us - to install the VMware Tools version of ESXi 5.0 instead.
This reminds us of the fact that VMware has changed their VMware Tools support policy with the introduction of vSphere 5.0: The VMware Product Interoperability Matrixes now include a selection for the VMware Tools, and it shows that the Tools of ESXi 5.0 are "interoperable" not only with ESXi 5.0 but also with ESX(i) 4.1 and even ESX(i) 4.0:

VMware Tools Interoperability Matrix

 ... whereas earlier versions were only interoperable with the corresponding ESX(i) version.

So, if you are still on vSphere version 4.1 or 4.0 and are planning to upgrade to vSphere 5 sooner or later then you can start deploying the VMware Tools of ESXi 5.0 now, and avoid the effort of future tools upgrades.
You can download the latest version of the ESXi 5.0 tools here at packages.vmware.com.

If you run a manual custom installation of the ESXi 5.0 tools in a Windows VM you will notice that there are some new components included:

VMware Tools 5.0 components default selection

The default selection of components (this is what you get when doing an automatic install or upgrade) is now more suitable for VMware ESXi than it was with earlier versions of the tools, but it still includes two components that are useful for VMware Workstation and completely useless when running ESXi: the Record/Replay Driver and the Audio Driver. Earlier versions of the Tools would also install the Shared Folders component by default, although it is also only useful with VMware Workstation.

A last hint: There is still another "feature" in the VMware Tools package for Windows that I personally find very annoying: Once you have installed the Tools you are by default not able to modify or repair the installation through the "Add or Remove Programs" control panel applet. To fix this find the GUID key for the VMware Tools package in the registry under
   HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall
and change the NoModify and NoRepair values there to 0.