I have both Rag 2 and MJ3, currently hooked up YGGY OG A2.
Rag 2 is better with my Hifiman HE6SE (non v2)
MJ3 is better with my ZMF Auteur Classics... MJ3 has better instrument and vocal separation, more feelings of depth and separation, little bit more fine detail/plankton.
I think Rag 2 has a little better bass control than MJ3, but MJ3 is equal to or better then Rag2 everywhere else... but not by much. Rag 2 does speakers and has three gain levels & has better volume control with its 128 step attenuator.
Both amps drive Focal Clears, HD6XX, HD600 very well.
I love both amps. Can't go wrong either way..
MJ3 has a bit more emotion and bob your head feel to it. aggressive. confident.
Rag 2 is a bit more even keel, detailed, smooth, less bob your head and groove, more kick back and admire how smooth and refined it all sounds. Less aggressive and not outwardly confident. Reserved, self assured, not flashy, but decidedly confident and will kick your ass if you mock it....