VMware round robin load balancing

I have been curious to test out round robin load balancing in ESX 3.5. Recently I have been only working with Clariion (active/passive) arrays. Now at my new client they have active/active arrays (Symmetrix).

From my understanding the way it works is it will push I/O on an HBA path until a set amount of blocks are sent. At that point it looks to see which HBA has a smaller queue and it will use that path until the number of blocks is reached again.

You dont have to set it like this. You can have it use a preferred path, etc., but this option seems to make the most sense.

I dont know if this is how it really works, but that is my understanding. Pretty cool stuff if it works. As to this day it still says experimental.

Anyone use this?