For me, the Ox was key in making the first satisfying profiles of my amps.
I started with the Behringer DI; bought a Countryman; and also tried to mic up my cabs both direct into the Kemper or with a combination of mics/preamps/mixer in my bad-sounding room. The profiles were okay, but didn't want to make me give up my tube amps.
After buying a PRS DG30 head, I got the Ox to use as a reactive load. Only after owning it for a few months did I think to try it for profiling.
For the first time, I could use a proper A/B setup with the internal profile and reference amp during profiling. When I heard the first profile results, I knew my problems were over. The profiles are accurate, feel more alive and dynamic, and are inspiring to play.
The only adjustments I made to the Ox rig preset I use for profiling were to mute the room mics, and set each cab mic to on-axis. My ears usually prefer an off-axis sound, but the Kemper seems to like the brighter response - likely gives it more frequencies to work with and analyze during profiling.