We are starting to deploy the GSX internally at JD Edwards. Not sure if we have the metrics, but I will check.
AFAIK, the ESX runs better by allowing you to parcel out the host resources with more control. It will look to SQL like a separate machine, the resource management peices of VMWare are inivisible to the Windows OS, and need you to manage them.
Steve Jones
sjones@sqlservercentral.com
http://www.sqlservercentral.com/columnists/sjones
http://www.dkranch.net