If you'd snap your fingers while listening to your Mojo to turn it into a Hugo the first thing you notice is that the music sounds larger and more spacious. There is quite a bit more perceived bass and treble because it isn't rolled off like the Mojo. So it's a more visceral listen, and the added treble is probably what helps the sound stage to open up, and the difference is quite big here. I think the Hugo is clearly better because it's a case of "more of everything", but it only excels with a good source. Mojo is smooth and polite, and that really helps with making it work with whatever partnering equipment and source material. Hugo can and will bite if you give it a noisy signal or a bad recording. For me that means using Hugo with my Allo Digione at home, and Mojo on the go. I bought the Hugo as a 2nd hand bargain and the Mojo new fwiw, so I have no purchase confirmation bias that steers me in the direction of the Hugo.