I have the Mishimoto fan shroud, on a PWR radiator. Depending on your location, it may or may not work. It works for me alright in colder climates, but down in Vegas and Phoenix, it does NOT bring enough air through the radiator to keep things comfortably cool for my taste.
However, in my case, I have what may as well be the biggest radiator you can get for a Mk3. It was pointed out to me that yes, increased capacity can help cool things, but if you can't draw enough heat out (through the fans), your giant radiator is essentially a giant heat soak. For all I know, this fan setup may work fine in hotter climates with a *smaller* radiator than the PWR. Seems backwards, I know, but it makes sense to me...