Howdy,  
I previously asked this ServerFault question:  Does anyone have experience with lefthands VSA SAN
The general consensus looks like it does not perform well enough for a production SQL server even at a light load.  
So the new question is, How does LeftHand's SAN perform on the HP or Dell dedicated Hardware boxes? 
We are looking at the Starter SAN with 2 HP nodes in a 2-way replication, 2 ESX servers hosting a total of 2 Active Directory server, 1 MS SQL server, 1 File Server, and 1 General Purpose Server for things like Virus Scan (All Microsoft Server 2005 or 2008).  
The reason I am looking at LeftHand is for the complete software package.  I plan to have a DR site and like how the SAN can perform an Async Replication to the offsite location without having to go back to the Vendor for more licenses.
I also like the redundancy built into the Network Raid architecture.  
I have looked at other SANS and found different faults with them.  
For example, Dell's EqualLogic: Found that although the individual box is very redundant in hardware, the Data once spanned across multiple boxes is not redundant, if a node goes down you have lost the only copy of the data sitting on that hardware (One thing is certain, all hardware fails... When? is the only question.).  
I have used an XioTech SAN as well.. Well worth the money BTW, but I think it is overkill for the size of the office I am targeting.  The cost to get the hardware redundancy in the XioTech makes it a little out of reach for the budget I am working in.
Thank you,
Keith