I uploaded fw3.0 to my x3 and saw and heard many changes to the x3 with this new firmware. All of the look and feel changes are great. I liked the expanded volume granularity.
My first listen, I do not remember what resolution of files I put on, the sound seemed more spacious than fw2.1. But it was a cursory listen for background music.
Upon first critical listen of some 24/96 flacs, the performance was so poor I unplugged the X3 and put on a CD instead. Songs had horrible audio dropouts to the point of making it unlistenable.
With the 2.1 firmware the X3 sounded so wonderful that I never questioned its' audio performance. I just enjoyed fantastic sound.
I went home and assured myself that the problem was not with the flac files by playing the masters on my computer with foobar glitch-free and wonderful.
So I reverted to fw2.1 and now my audio is back to wonderful, but now I am skeptical of FiiO truly doing audio QA on their firmware upgrades.
These audio problems were on my X3 with a PNY 32GB class 10 microSD card that I had listened to prior to the upgrade without audio issues, and am presently listening to with my X3 running fw2.1.
So please fix the 24/96 flac audio issues in fw3.0.
Thanks for your support. Love the product!