Hello SRemsing,
The safe answer is "It Depends".
Adaptive queue throttling can occur from either PORT congestion OR LUN congestion. So depending on how your environment uses the storage, and how busy it is will determine if you need it or not.
When the number of QUEUE FULL or BUSY conditions reaches the QFullSampleSize value, the LUN queue depth reduces to half of the original value. When the number of good status conditions received reaches the QFullThreshold value, the LUN queue depth increases one at a time.
For 3Par arrays its recommended that QFullSampleSize is set to 32, I would suggest QFull
Threshold to be set at 8. No HBA settings required that I know of.
Disk.SchedNumReqOutstanding is a per virtual machine setting (CORRECTION: its a system wide setting that effects Queue Depth per virtual machine --RS ) .
If you havn't already, take a look at:
http://kb.vmware.com/kb/1008113