I was testing the Cayin N5 for one week as part of the world tour. As there are already plenty of pics, I decided not to take any by myself - they wouldn't be even close as beautiful as from other reviewers and this DAP just for its looks deserves some nice high quality pictures.
Please also keep in mind, that I'm not a professional reviewer, so these impressions are from the perspective of an ordinary user, smooth sound lover and average basshead.
 
Testing equipment:
Phones: Unique Melody Merlin
Amp: Cayin C5
Comparisons: iRiver H320 Rockboxed, Fiio X5 1^st gen, iBasso DX90
Tested on low gain - on high gain there was too much hiss on my CIEMs
 
Functionality:
1. Good UI:

1. clear menu and it's easy to navigate
2. similar to Fiio DAPs, so you might feel very familiar

2. Average button positioning:

1. M button to close to volume adjustment buttons
2. you need to get used to the wheel (although it's a lot better than the one from Fiio X5) – I prefer simple buttons

3. Software:

1. track skipping is not working when screen’s off (probably fixable with future firmwares)
2. play/pause takes too long to initiate (probably fixable with future firmwares)
3. couldn’t test DAC due to driver issues (probably fixable with future firmwares)
4. missing dynamic playlist option, which is a big downside, if you’re used to Rockboxed players

 
Sound:
- on the warmer side
- enjoyable and emotional – not for analytical fanatics
- a bit harsh with bright mastered tracks, but in general quite smooth
- with C5 – full bodied sound, adds bass power, a bit more warmness and soundstage
 
Bass:
- good extension and slam
- pretty fast and detailed
- good transition between subbass and midbass – nothing too dominant, nothing too shy
- no bleeding into mids
 
Mids:
- smooth, musical
- intimate, great female vocals
- drowns you into the music – simply relax-and-enjoy kind of presentation
 
Highs:
- quite detailed and extended, but not boosted
- crystal clear
- rarely on the edge of harshness (there's some peak in the upper mids/lower highs, which I'm quite sensitive to)
 
Basshead perspective:
- good basshead levels, but not for extreme basshead lovers
- no precut option like on Rockbox, therefore the bass distorts quickly with heavy EQing – I prefer using EQ, than bass boost on C5, which muddies the sound too much
 
Comparison to other players:
- from memory though, as I don't have the Fiio and iBasso anymore:
vs Fiio X5 1^st gen. – N5 is more neutral, more linear in bass, a lot better scroll wheel. X5 had no issues with DAC drivers from the beginning. Similar UI.
vs iBasso DX90 – quite similar sound, but DX90 is a touch brighter. DX90 has Rockbox, although it wasn’t pleasant to navigate it with the touch screen.
vs iRiver H320 (if it matters to anyone these days – similar sound, but N5 had a bit more sweetness in the mids. Due to Rockbox EQ capabilities the iRiver can be a true bass monster.