When I started PC gaming in the early 90s I learned to associate sound cards with driver nightmares and incompatibility. I had a succession of IDE, PCI Creative Soundblasters which, well, functioned. Mostly. When motherboard audio became widespread, decent sounding, and widely supported by software I mostly stuck with with the easy solutions. My most recent motherboard (Asus X99-A) even has relatively good quality sound. Nevertheless I was aware that my Sennheiser HD650s were badly under driven by this setup. I wasn't interested in the clutter of an external solution and most internal soundcards are dubious gamer-bait with surround sound fakery. That's why the Nu, a quality 2 channel solution, was so appealing to me. The Nu is exactly what I was looking for and it sounds fantastic.
Cons: For some reason it did not work on the bottom PCI express slot on my X99a so I had to reshuffle some cards. Occasionally the card stops outputting audio when the PC wakes from sleep requiring a full reboot (some things never change with PC audio). Hopefully that is a driver issue that will be addressed in the future.