All I can say about the sound q issues is that I used to hesitate using the mk I as a mixer for my other gear, resorting to ”aux use only” strategies etc… Was probably user error in hindsight…But now with the mk II, I’ve never had things not sounding ”proper” and will not hesitate using it as a mixer for anything.
this doesn’t make the mk I unusable, you just need to pay attention when using it… whereas I feel like the mk II is forgiving in this area and lets you be sloppy with things. Hope this makes sense.
When using the OT to play back samples from other sources (ie not sampled by the OT) I’m sure there is no practical difference between mk I & mk II.
I don’t claim to be an audiophile but I generally trust my ears and have read enough about the technicalities of analog & digital audio so that I know ”not all gear is created equal”.