The plan 9 interface has evolved quite a bit, but it's largely invisible in screenshots. The differences are in things like triple click behavior, jumps to insertion points, effective use of mouse cursor warping, chording.
replyScreenshots -- or GIFs -- of Plan 9 compared with Inferno would be most instructive.
replyThe Plan 9 folks I've talked to are a bit shocked by this, but I preferred Inferno's GUI to plain old Rio/Acme etc.