Gortee, thanks for publishing that blog post. Only one question so far...
AIUI, a host can send a RTPG command to an ALUA array concerning a particular LUN, and thus learn the best port on which to access that LUN. That seems to be the ultimate high speed low drag way to handle pathing. The array keeps track of LUNs and ports, the ESXi host simply does what its told ("Access LUN 82 on my port with WWN xxx") and focuses on running VMs and crunching numbers.
At least at the enterprise, cost is no object level, why isn't this architecture pretty much universal? Cost? Inertia?