you are right. It shouldn't need to be so confusing, but it is.
The original XO was a TIROS luxeon I spotlight. The XO name is now bestowed upon a new light having a reflector. It has changed (to have a larger reflector rather than the sleek design previouslyused) into a shape looking similar to the XO3. It is still a lux I.
The original XO is now called the XO2 and is the same light it was before the change. It was only a name change.
The XO3 is a TIROS spotlight. It is a luxIII. It is basically identical to the T3 except it has no clicky and knurling. It has a twisty.
Wheeew.....that is confusing. Hope this helps.