I got the UE6000 (78 EUR
) after having the UE4000 (20 EUR) and being amazed about their design and comfortable fit.
Sound of UE4000 was so-so because I own the CAL! and a Teufel Aureol Real (100 EUR open around ear headphone from German maker Teufel - definitely worth a buy!) which are far superior but for outdoors in noisy street life the (too) strong bass is really good. I missed the highs on the UE4000. But it burned in and get a bit better.
So speaking of burn in, the UE6000 was terrible at the beginning! My Teufel Aureol Real and CAL! were far superior in every aspect.
But I gave them time to burn in. It helped a lot to get this awesome sound.
At the beginning I had the feeling, that the left can produces more bass so the balance was towards the left! I hated this. But it got better after burn in as well. Maybe when you have batteries inside sound gets out of balance, so I put the batteries out. With ANC on sound gets a subwoofer-loudness-madness ... I hate it!
Now as sound get's better and better I'm not sure it my Teufel Aureol Real is still better. But they are 2 different constructions so the open Teufel plays wider and more "airy". On top of this Teufel has better high extension um to 20kHz and in this area sounds more detailed. The tiny but very tight bass kicks just right but quantity wise I wished there were a louder bass.
UE6000 has kinda cut highs but far less than the muffled UE4000. UE4000 has much more bass quantity wise. Quality wise UE4000 is of course inferior to the more balanced UE6000. UE6000 sonds bigger too.
The CAL! sound wider - the UE6000 closer, especially vocals are on the UE6000 better, more positioned than more up in the air on the Creative Aurvana Live! The CAL! has more bass toward the lower frequencies whereas the UE6000 has more upper bass and more fundamental but unfortunately less lower bass.
So the CAL! is very open sounding closed headphone with boomy bass - the UE6000 is more precise and balanced. The CAL! has more highs but the UE6000 sounds better to me in this region too.
Both are good and I still like the CAL! It's like a subwoofer but without too much bass, it's just right.
Overall the UE6000 is the best headphone so far I own.
The Teufel is still close with it's more detailed highs and it's ope character and very tight but a bit tiny bass.
The CAL! and the Teufel Aureol Real are unbelievable light and comfortable headphones. The UE6000 is very comfortable too but lots heavier and it is very noticeable in comparison.
EDIT:
they getting better and better with every day burn-in
I own the Nokia BH-905 Bluetooth noise cancelling headset (can be driven with cable as well, mediocre sounding, nothind special, very bad looking btw. I'm using it only when cleaning at home LOL
).
It cancels noise very very good. In comparison the ANC on the UE6000 is really non existent. But I don't care the active sound is not my taste anyway... And for walks I have the good isolating UE4000
https://flic.kr/p/ob9GuT
so yeah, im not genre specific about this.. Let me know guys, UE6000 seems to be a pretty sweet pair of headphones. Sadly, here we dont have an option to check it out first before ordering. Just about everything comes online 
