I just got these yesterday and am impressed enough to write this while drinking my morning coffee, which is quite a compliment. One key point I would make is that while several reviews mention a V-shaped sound signature and strong bass, how noticeable that is will depend on what your previous headphones were. To me, the bass in the JVC S500 I was using felt excessive at times and I was nervous that these would be the same. In reality, the bass in the 681EVO feels perhaps a tiny bit less pronounced and I like it. Overall, I'm impressed with the sound. Vocals sound alive, guitars sound great, drums are okay, and the soundstage feels spacious.
Other bullet points: The accessories are welcome. I switched to the velour pads immediately and prefer them. The 1m cable is great for my mp3 and being able to switch it is welcome. Isolation is noticeably worse than the S500, but that's not a surprise. To my ears, these sound better than my xiaomi piston 3.0.