What exactly do you want to know, we have some and have tested a lot.
The paper stock is super important for acceptable results. The machine does not compete with a Xerox Docucolor or Konica 6501. The images can be light and washed out at times with a poor stock. No coated stocks can be ran on this unit.
Riso has in about the last year has partnered with Kodak to do reprints for work done on a Kodak Versamark web inkjet, the quality is on par with transpromotional market, but can be better with a optimized paper.
It seams to be a better fit more for inplants, and schools that want color at a low price.
The speed is great through the only other sheetfed machine that can compete is a HP indigo 7000 running 2-up, then both can do 120 ppm.
This machine was/is kind of ahead of it's time. Prior to Drupa no other sheetfed inkjet was close to it, now the Sceen and Fuji concept presses have the ability to inkjet print onto sheets and in larger sizes.