Great demonstration. This is exactly what I have issues with. You can obviously hear that the second and third attempt sound so muddy and crappy compared to the first "trick" (dim 800 style). Why did Pioneer change this? Part of my style of mixing is using the echo post fader and I just can't do it on the 900. The 800 echo was way more intuitive to use you could almost slap the fx button on and off and it would sound fine. Just seems weird to me they changed it as I've never heard anyone complain about the 800 echo and now there are at least three of us here on the forums with strikingly similar issues with the 900's echo.
BTW, I was able to re-create your trick by flicking the fx select knob and it works like a charm. I guess I'll resort to doing this for the time being. Hopefully enough of us will come forward so that Pioneer might take our complaint seriously.