In relation to the MSL SUT, there is a particular Tonal Quality Japanese Audio Enthusiasts seemingly lean towards, which is for the Rich Tone.
The MSL SUT may? be voiced to create the perception of rich tone is increased to compensate for the Cart' user that desires for more of Rich Tone than the Cart' is able to produce in a typical MC Input.
I like @mulveling have quite a few SUT experiences behind us, and even though we lean towards different sides of the Rich/Lean Scale, we both know SUT's can be perceived as unbearably overblown in the Lower Frequencies, to being perceived as Lean in the Upper Frequencies.
What really matters is where the individual chooses to hit the stop button and get of the Bus on the Rich/Lean Route.