I've been using the UA2 with a pair of Shure SE846s and I must say the sound quality it brings out on high res tracks is great, it also gives a decent volume boost that makes it useful for listening with larger headphones.
It is however not perfect, I've found that there is an issue where the audio cuts in and out on some devices, particularly on my Windows 10 Dell Inspiron 7566 and Windows 7 Lenovo P50 laptops (I did install the drivers from the Shanling website). It also does cut in and out on rare occasions with my Galaxy S10, although this may possibly be due to a loose connection when moving around with my phone. I'm not entirely sure if the issue is on the UA2 side or my device side since it works flawlessly on my PC (Windows Server 2019) and iPad Pro. But having said that, even with the issues on my laptops it is still well worth the price.
If you are looking to get into high res music I highly recommend the UA2, this is my first high res DAC so I can't really compare to anything else but I can definitely hear the difference. Maybe just be a bit wary that it may not work properly if you plan to use this with a Windows laptop.