FWIW, I have been using Neutron quite a bit with a project I'm mixing. How I like to use it is to see what it comes up with, then approximate it with EQ and compression I prefer to use instead. So I like using it for "analysis" purposes more than anything. Sometimes it's good by itself, so I leave it. But if you pull up it's settings, then pull up your own EQ and replicate what it did that you like, then move to the compression, etc. tweak it to sound the way you want and remove Neutron after you are done, it's really helpful that way. I personally hate the Exciter it likes to put on things--especially on bass. Neutron overall likes to add a bit too much high frequencies for me (as does Neutrino), so if you use it across the board on everything, it will be a pretty top-heavy mix. At least that's been my experience. For less experience mixers, all that extra high end across all the tracks may sound more "exciting" when each one is isolated, but it's ear-piercing once it's all added together. But that doesn't mean it's not an excellent tool when used to help you make decisions and spot problem areas faster.
Ozone is used for a very different purpose--mastering when all is done. You can use it for other things, but that is what it's intended for. I don't see much overlap in the two products at all. Plus, the CPU hit if you tried to run a ton of Ozone instances across a bunch of tracks would be major. The individual Ozone plugins that come with Advanced may be a different story though. I got the Standard for both, since I already have a lot of great EQ and dynamics plugins. I didn't see any need for the Advanced versions myself.
Just my observations. Both GREAT tools to have though.