The jury's still out on uncompressed FLAC. However, I finally can describe an analogy to lots of members here how I hear AIFF vs. WAV.
Lots of us here have done comparisons of playing the same file via Roon and via MPD. IMO, WAV sounds like MPD, and AIFF sounds like Roon. I think FLAC uncompressed is more closer to WAV than AIFF.
On midfields in a 20x60 room, there's enough space to hear that WAV has more depth. AIFF comes off as flatter. WAV is more liquid like as well.
The release in transients in WAV sounds more satisfying. AIFF on the other hand seems to be loading up on the attack. I'd recommend playing a few tracks with just vocals and a solo instrument or drums. This can make AIFF sound tighter and upbeat, however, this may not be natural. In long term sessions, I find WAV always wins.
I also find WAV to go deeper in bass, with AIFF having more midbass presence. This could be due to loading up on the attack. The difference in how vocals are rendered tonally and in the soundstage is also apparent. AIFF makes it seem like it's more detailed and how you can visualize it better in direct fast switching comparison. I'd say it sounds more raw, but potentially processed. WAV on the other hand sounds more relaxed and timed correctly. The sound originates from a deeper point.
So depending on how somebody's system sounds, they might very well prefer WAV or AIFF, just like some prefer MPD or Roon (sonically). I think those with a sloppy system might like AIFF as it makes it tighter and more detailed (like turning up sharpness on TV or DSLR, even if something isn't there). If you already have a top front chain and TOTL tight speakers, you'll enjoy WAV. It's the long listening session KING.
If I had to bet and invite an artist and playback both WAV and AIFF and ask them without telling which one sounds more like themselves, my bet would be WAV.
Next up, nailing down FLAC uncompressed.
