I have both an XO3 and a T3, and both beams look identical to me. I believe that any slight differences in brightness and tint must be attributed to the Luxeon lottery. Variance in beam shape are probably due to manufacturing tolerance re. positioning of the optics. And of course the T3 is slightly, but negligible, heavier due to the knurling. However, the knurling makes the T3 much easier to handle, if you have slippery hands, like me, which makes the momentary switch of the XO3 difficult to handle.