Thanks for the review, Garfield. I've updated the table with a footnote and an accurate price per usable port.
I was actually considering hunting this hub down, when I saw on photos that it had to power connectors, which I thought would mean it could be powered from two adapters. Strange that only one of them is wired.
Just so there is no confusion, there seem to be two versions of this hub. one with an aluminum enclosure
http://usb.brando.com/usb-20-port-hub_p03123c039d015.html <- this is the one I actually bought, and that does not work with more than 12 miners.
(the one I purchased with 1 spot for a power adapter)
and there is another one that just has support plates, that has 2 AC adapter plugs available, but I do not have that one to determine if that one has the capability to run 20 miners at once.
similar to
http://usb.brando.com/industrial-usb-16-port-hub_p01936c039d015.html but I have not been able to find a place to purchase it from that is reasonable.