I have both and prefer the mojo with both iems and hd600s.
Can you go into more detail or do a review on both the Mojo and International+? And preferably with your HD-600s since they neutral and I'm very familiar with their sound signature. In the real world (e.g. on an airplane) I would never use the Mojo or International+ with the HD-600 but for review purposes it makes sense. These two amplifiers seem like the best two fighters to put in the ring and it will be interesting to compare them.