oh, I have this one!
hmmm, it appears the goal of sonarworks is to flatten the response of the headphones and taking into account the head between the phones?
isone adjusts the head between the phones, and has different frequency responses of various monitors, etc. also allowing the angle of the speakers and monitors to be adjusted, and room size, distance from speakers,etc.
I'm not sure I'd say the sonarworks is more detailed, just flat frequency response. They also have a speaker calibrator for flattening the monitor response. The idea being that it doesn't matter what headphones or monitors you use, expensive or cheap, that they level the playing field by offering a flat frequency response. I suppose you'd have to a/b various headphones and speakers to see how well it works.
isone takes a different approach by using binaural setup to adjust for head interference to get the sound more like a speaker setup. I believe one of the monitor presets A, B, or C is suppose to emulate Yamaha NS-10's, there's different presets and frequency response curves, I think you can even change the frequency response curve to be flat.
The whole thing to keep in mind about reference monitoring, is that it is just that, monitoring, it doesn't add or take away anything, true, it may cause you to add or takeaway, but still the whole point in using reference monitors is IF they allow you to mix for a compromise that sounds good on the greatest amount of end-user listening systems. It doesn't matter how flat the freq. curve is. It's whatever you need to make that translation. That's sort of the story behind the NS-10's, and there is even some argument that you also need to set them on top of a console?
No one will ever really know for sure what you mixed on, because it's mostly about how well the mixer translated, or what the listener is listening on,lol!