Picked one of these up. I have a 512GB card almost filled with FLAC files and it detects them all no problem despite the site saying max 256GB.
Only have about 3 hours of listening so far, but they drive my OG Campfire Andromedas very well. I don't hear any hiss.
The size is perfect for me. The Fiio M11 Pro was so heavy and clunky, that it was almost a pain to carry around. The screen is big enough, so I don't really fat finger while browsing and can use it just fine with one hand without feeling like I may drop it. The edges are very sharp, even more so than the M11 Pro. I have the leather case coming, so that shouldn't be an issue.
The EQ options are amazing. I haven't had time to sit down and mess with some custom EQ and a lot of them seemed to bass heavy and narrow the sound stage. For now, I've been using the 'Rap' preset as it sounds the best to my ears. Anyone care to share their EQ settings? Gapless playblack works properly, unlike the M11 Pro.
The software could use some work. Background images and player skins look like they were copied from 90's Winamp skins. It doesn't bother me because 90% of the time my screen is off. I opted for 'Black' background with 'Type A' skin. It'd be nice to see some more customization options or ability to create our own themes, but I doubt that will happen. I haven't figured out how to display lyrics properly. Right now they're stored in the FLAC tags and the app doesn't seem to detect them. Their website says they support tags for lyrics, but I have a feeling I'll need to export to .lrc. I'm just afraid adding a bunch of .lrc files will cause issues.
Navigating music could be a little improved. If you're searching in 'Folder' mode, you need to back out into the root directory to change to a different mode of browsing such as Artist/Album/Playlist/Genre. Folder mode is the only way I've found where it automatically goes to the next album, so most of my time will be spent in that mode anyways.
The LED feature where it changes colors depending of the quality of the music is kind of pointless IMO, so I turned it off. Calling FLAC 16bit 44.1kHz files 'Standard' seems weird. I don't know anyone who can blind test 16bit vs 32bit FLAC and be consistently correct. I also don't get the buzz behind DSD. I think 128kbps-320kbps mp3 should be standard, FLAC should be HD, and then have a Master/DSD color.
Overall, it's the best player I've found for my Campfire Andromedas. The software is easy to find the music I want to play and the it sounds amazing in my ears. At the end of the day, that's all that matters.