They got the December PS4 and X1 NPD numbers right..but that's cause it was pretty easy due to access to public information, even I guessed it as correctly as VGC did lol. Wouldn't be surprised if he did the same math I did instead of whatever made up methods VGC is supposed to have. Now that such info is no longer helps with new numbers it is back to being completely wrong.
He took the japan numbers from MC/Famitsu and applied the same % drop to his previous PS4 US numbers, without any thought. Of course, somehow the X1 had the lowest drop out of all systems in every region. All this makes complete sense.
It makes perfect sense. ioi doesn't give a shame anymore. Therefore, I don't give a shame about his site