hi kloss, i did compare the N3 and M6. these are my opinion tested both with ath-ar5bt and KZ-zsn
sound : M6 sound signature is leaning a little bit bright becasue i think that's the sound signature from Sabre DAC.
N3 have warmer sound to me than M6. But still its very dependable from what kind of headphone you use. Because i think the diffrence between these two quite thin. Unless you sit at home and spend few times A/B comparing, you wont notice the difference.
they both two have small difference also in power output. its on 20mW at 16ohm. M6 have 110 mW and N3 have 130 mW at 16ohm. so from power output also you will hadly notice the difference.
EQ settings : sure M6 would be looks easier oing EQ settings with those touch screen than N3. But here's the Problem. When you doing some EQ in N3, despite EQ off or ON ( but flat EQ) the sound wont be any difference, unless you really tweak the Eq then the sound will be change. On M6 the sound will be change (sound like the volume cutted) the moment you turn On the EQ setting, even the the EQ is flat settings.
But for me its no biggie, i never tweak my EQ anyway. i like the difference characteristic from each headphone or IEM
i did buy sony NW-a35 before i bought M6. Because with Cayin N3 happened so many times accidental press when im looking song in my list. there's no LED lamp under the touch indicator on N3. And also because the touch panel is too sensitive happened also the accidental press. To be honest, its almost 2019 and i think N3 UI is so oldschool and quite boring for me. Im tired every time my friends saw N3 they asked is it mp3 player or what, i had to explain it. not that i care what they think, but they always asked when im trying enjoying my music and it was annoying for me.
after i bought NW-a35 i fell in love with the UI and how it looks and feel on your hand. with that full touch screen its easier to go trough your songs, Plus Sony make their own DAC chip resaulting sony signature sound diffrent than other open market DAC like sabre, texas instrument, or AK. And dont make me start with the LDAC Bluetooth, its just Superb. And the Battery last really long, with my song most are FLAC, takes sony around 30 Hrs playback. the Only letdown is the Poweroutput. i dont know if sony so confident with their amp Chip or they purposely build the NW-a35 for IEMs only, it has only 33mW at 16 Ohm -.- unless i stacked it with an my Fiio A3, i was dying driving bigger impedance Headphone. What right ? even Fiio M3k have 35mW powerouput and it cost only €70. i forget one thing, that freakin sony cable -.-
then god answer my prayer
came M6 with all the preks i love from sony NW-a35 ( besides the sony DAC and AMP chips) and the power almost like N3. Gone all my Problems, im commuting now with M6 sits perfect in my pocket with great SQ and at home i can enjoy new perk from M6 ( stream from spotify ), wich i didnt get with NW-a35. even poeple see you at train or your freinds see it, probably they will think its a smartphone anyway and wont bother you when you listen to your music. And dont Forget the screen bro, its comparable with the hiby R3.
but than again it depends on what you need from a DAP. i just hope my experiences could help you spend your money wisely
cheers bro