I'm on an Oregon Coast state park camping trip. I've tried putting my two primary cameras on their highest ISO setting to create lots of noise. The new AI noise reduction (in Lightroom for me) works quite well. I think on more "normal" images, the old sliders might do a more "gentle" treatment. It is going to depend on your images and your taste. For me, it is going to be useful for hand held, long lens images. I can intentionally crank the ISO up and fix most of the noise.