This tool continues to get updated (thank you Jeff Purcell who did SO much on this and the previous release, Dan Baskette and the Celerra team!). You can get the latest version here:
This version is much faster - at least 2-3 times faster than the old one. In terms of speed, I think it would be hard to get faster than this - in our "playing around", it's at least 10x times faster than the upcoming View Composer approach.
So - does that mean we think the array is the place to do this rather than the ESX server (aka VMware View Composer) long term or in all cases? NO.
There are so many things that can be done re: image preparation and handling and management better at the VMware layer than the storage array layer - which are both as important as speed. All the approaches have similar cost savings.
We're embracing the upcoming stuff (stay tuned - another blog post coming on this in a couple weeks). Over time, we're going to work to merge them as much as possible (i.e. use the VMware View tools to manage, but where speed of mass distribution is the key - you can choose to do it at the array layer rather than at the VMware layer (but it's managed at the VMware layer).