SuperUniti is boring! I would rather get a ND5XS/Nait5i-2 or ND5XS/NaitXS depending on your speaker.
In fact, I'd rathe do the UnitiQute if your speakers are a light load.
I had the SuperUniti for many months but sold it. Much prefer the UnitiQute into Harbeth P3ESR speakers.
The Uniti - 2. No idea: If it's really based upon the Nait 5i-2, I'd probably prefer it over the stuff mentioned above. But it does have a CD player which is something you're paying for unnecessarily if you don't need it.
Agreed, if the speaker load is not too difficult a UnitiQute is much more fun and involving to listen to.