As an owner of iK multimedia's ARC II speaker calibration, I was curious as to how the two systems compared. First off, the Systemwide feature of Sonarworks makes it the winner - period. The abililty to apply the speaker correction pretty much anywhere in your system , not just in your DAW, makes it incredibly useful - for watching Youtube or listening to iTunes. The ease of the calibration is another winner - much, much easier than the ARC. And it sounds good. I feel I can trust this calibration more than the ARC. I have been a fairly longtime user of Sonarworks' headphone calibration system (I own a pair of calibrated Sennheiser 650s), and I like that now I have my headphone and speaker calibrations in one place. Prior to Systemwide, I had one monitoring chain setup up with the the ARC and one with the Sonarworks - which was a pain. So, I would highly recommend this software. I would also recommend that you acoustically treat your room as best you can first, to lessen the effects of reflective phase problems.