Visually they can be stunning, you are limited on space though and have to really think out your rockwork. Mine was to small to put a sump in so I was always battleing nitrates but I thought it was pretty nice. Upgraded to a bigger tank and my son is getting the 35 hex.
The reason I am asking is because in the past week my fiancee has seen how dissapointed I was that I had to sell my nanocube...which I am still in the process of doing. It was necessary unfortunately (everything worked out, got a new car) but sad nonetheless.
My original idea prior to the nanocube was to get either a hexagon or a tall cube and simply make it a FOWLR. Now I am reconsidering that idea.
Because of this the flow wouldnt be as important. I was thinking a few Hydor Koralias or Tunze Nanostreams in the back corners to give about 20-25x turnover. A hang-on protein skimmer, heater and a pendant light.
My fiancee is hinting at a new setup as a graduation present for me so she has encouraged me to look around for what I might like.
The reason the hex or tall cube works is because of my space limitations.
I have a maximum of 30" wide (which is cutting it close) x 30" front to back (including equipment hanging off the back).
A 24" x 24" cube or a 25" hexagon would work perfectly here.