I am guessing you mean audible by worthwhile. Really? No. Psychologically? Maybe yes.
The differences are lower then -110db. So inaudible, but your brain is amazing and will hear more depth, tighter bass and nicer soundstage.
People who have already invested will claim they hear it. I run an even older interface trhe ADI8 AE. Which is a ADI8 DS mk1 with noisier AD bur same DA.

Real blind testing always reveal that things are not that audible. Even Amps, where the were blind tests between  $100 to mega expensive amps. Conclusion was no difference with a slight advantage for the 100$ amp.

Thank you for the replies... I suppose of course it is a matter of opinion with what we think we can and can't hear.
I'm pretty sure I can hear a noticeable improvement in DAC between my UCX and ADI-8 DS Mk III on Barefoot monitors in my somewhat-well treated room. To me that is definitely a "worthwhile" jump in quality and justifies the equipment.
Does anyone think I may notice a similar improvement in quality between the somewhat old ADI-8 DS Mk III and the new ADI-2 DAC? I'm not familiar with the different converter chips used in the ADI line over the years and how they may have improved.

Also follow up question- I had a glance through the manual but I'm a bit unclear on how the USB connection could integrate into my setup. Is it possible to use the USB connection on Windows in tandem with my UCX (also connected by USB) and be able to route my master out to the ADI-2 DAC, or is the only option to connect a spidif/adat cable from the UCX? Thanks again