The Mobius actually has a companion app that allows for input of the user’s head circumference and inter-aural arc measurements in order to tailor the headset’s HRTF and 3D virtualisation to something more personal. I have one.
I don’t have a Super X-Fi dongle (yet) but AFAIK, it uses uploaded photos of the user’s head and ears to the same intent and purpose. Which is more effective, remains to be seen. From early reports, the Super X-Fi app has multiple headphone profiles (Senn HD650 being one of them) and I would imagine that the effect will vary greatly depending on the profile used and whether that profile matches the headphone connected to the dongle. I would wager best results would be from matching profile with headphones. I would contend that the Mobius would at least have an advantage over headphones paired with a generic or mismatched Super X-Fi profile as far as HRTF goes.
My own experience, I found entering my measurements to be a significant improvement, albeit not quite a drastic one.