[KusabiKuri]

I just recently got mine and have been using it with my Note 4 as well as my work and home laptops.  For IEMs I tried my JVC HA-FX700s and for headphones I used my Mad Dog Pros.  For speakers, I piped them in to my Audioengine A5+ set.
 
Initial impressions are that it seems with IEMs you get some white noise which is probably what the above poster was talking about.  With the Mad Dog Pros, I get none of that.  Sound-wise I don't feel like it's terrible but it's definitely not a huge step-up from internal DACs.  Not having a clip on the unit itself also makes cord length a little awkward if you're not using short-cord IEMs.  Maybe a MiniDisc-style removable clip would be helpful here.  Also, I have not upgraded the software yet as detailed by the kickstarter page, but the volume control when plugged in to a PC and using the on-unit volume control is absolutely horrid.  It has worked correctly for me exactly once.  The volume stays at something like 40-50% and you can't raise it, only lower it.  When in USB mode, your computer cannot control volume so you're forced to control it via the unit or a secondary amp (which was a non-issue when plugged into my speakers).
 
All in all, if they fix the volume-control issues and the background noise with IEMs, I'd probably use it more.  Until then, FiiO's offerings for the slightly higher pricepoint are definitely more polished and reliable IMHO.

 

[parthabhatta]

I bought a Aqua couple of weeks back and I am loving the sound. It's the best for listening to mass Market MP3 specially Indian Bollywood songs which are treble heavy and harsh. This DAC smoothens them and reduces listening fatigue. Moreover, it doesn't get heated up like similar devices I have, COVIA ZEAL EDGE, SABAJ DA2. Highly recommended for Indian Bollywood songs. I have tested it on my Xperia XA1 Plus with **** pt15 which is a bit analytical earphone. A warmer earphone may improve the sound further. I paid only 29 USD plus 8 USD for shipping while buying from their home site.