For anyone who was thinking about buying one of these, Rosewill has released a new revision RSV-L4000C that now has a redesigned rear window that has the PCIe slots removed and extra fan holes in its place as well as the chassis now has (3) 120mm fan placements in the front. Makes it a whole lot easier. I just received mine today and have a little work to do shoehorning my 1080 TI's in there.
Unfortunately this chassis still only supports 1 power supply which still boggles my mind.
I wish they had done 3 x 120mm in the middle and the back as well

And set the GPU support bracket so you could run it in the front or middle so you could use blower cards either direction.
One PSU will support 7-8 GPU's as long as they aren't 1080 ti's or Vega.
I'm working on getting a 2400w server PSU running in mine for an 8 x 1080 ti build that I'm hoping to finish and post up about soon

The IBM 2K power supply will fit pretty nicely in one of these even when flipped on its side, which the Delta 2.4K won't do.
You can find very nice break out boards for the IBM 2K sold by users on Bitcointalk.