Oh my man ... you haven't been around long have you?
At one point EVERY Calgarian had one of these. We were constantly mocked over it!! "You Calgarians and your square reactors."
I have about half of mine still (it's been pretty badly scavenged for parts in the years since I took it offline). The reason I discontinued using mine was that it was oversized, it took me 4 containers of ARM to fill it and at $30 per container that was starting to cost me a little too much to keep it running.
It's not a bad design, it's not the be all end all of reactors but it does have some merits. If you make one you won't regret it.