I bought the tiny usb dac on the hifimediy site last week because I was not completly satisfied with the sound quality of my samsung galaxy note II.
Before this, I tried to install perseus Kernel on my phone : it improves the quality, but not enough for my exigent ears.
I live in France and I received my tiny dac 7 days later. I'm very satisfied of my purchase. It works perfectly with the galaxy note 2 and the sound is very detailled, clear and punchy, just as I enjoy.
I own 2 dacs, a Ibasso D0 (Dac/Amp) and a HRT Streamer II. I compared them with an Objective 2 headphone amplifier and AKG 701 Headphones. The Hifimediy sounds much better than the IBasso : more detailled and more dynamic, with a flat frequency response. Obviously, The HRT sound is more refined, but It costs 7 times the hifimediy's price. And the tiny dac sound is not so far of the HRT....
Even If the headphone Amp improves the sound, you can plug the AKG 701 directly on the hifimediy, the level will be good enough and you can control the volume from your phone.
I would say this dac is an excellent choice for mobile purpose, which will get the better sound of an android phone for a very cheap price.