I love the Sony HAP-Z1ES.
The user interface is fabulous.
It takes some getting used to on the set-up side. You need your IT hat.
The CD to DSD upscaling engine is excellent.
It is a unique niche product, and other DSD DACS are available.
In fact I see that the Mitek processes MQA already.
However, for an all-in-one that supports an external drive via USB-2, has an on-board computer using Linux that presents an easy user experience, it can't be beat. It likes to run the show so if you're all computer fiddly, it's not your thing.
Oh, and it sounds great too.