I had this “masking”" feature and mixing assistant on a wishlist for Cubase two years ago. If Steinberg could imlement this also with internally and externally sidechaining; EQ, Compressor etc that would be great. Neutron is a beast though. The most revolutionary plugin in 20 years.
Neutron is great, indeed. I was a little worried that it would make pro-level mixing too easy for novices, but luckily that’s not at all the case. 
I say let Izotope do it since we already have it from them, and it’s done incredibly well and sounds top notch. And since Cubase has many other issues to work on, I don’t see a need. That’s my opinion, anyway!
sorry, I am not quite getting the topic title- is there a rumour/announcement of Cubase 9 coming with a stripped down version of Neutron? or should it read something like “Cubase9 vs. Izotope Neutron”?
It should read “I wish Cubase included these Neutron features”…
I really like Neutron but it is extremely cpu hungry on my system. I can use it in Cubase, but it doesn’t agree with Live very well and it basically broke Studio One (which I no longer use anyway).
I wish Izotope would release an update already that fixes CPU optimization, and hopefully eventually adds mid/side eq
So yeah, I’d love it if Cubase would include some of this stuff. So I can use it with less cpu drain
I would agree: It’s definitely clunky CPU-wise in Cubase, and from what you say it might be the same in Live and Studio One. Might be a VST issue with Neutron?
When I was still on Pro Tools there was never a hiccup when I analyzed the audio in Neutron and it loaded up faster and used less CPU, but in Cubase there’s a hiccup and it loads up slower and uses more CPU.