So, I upgraded to the HEKv2. I've had them for a while now and my feelings about them have been mixed. (when compared to the V1). The V2 are definitely more comfortable than the V1 and the headband doesn't move every time you take them off. I never felt the V1 build quality to be bad, but I was annoyed by the fact the headband adjustment moved too easily.
Sound-wise, it took a while, but I think I have a handle on what I"m hearing now.
Right from the start the V2's sounded a lot different than the V1's to me. I don't understand the reviews that say the differences are small. There are two main differences: 1. Soundstage, 2. Frequency response. Soundstage has a greater effect on the overall impression I have of the two and frequency response has an effect on DAC pairings.
Soundstage: I think what I'm hearing is that the V1 radiated sound into a "room" and the V2 don't. The V1 had greater space between the driver and the ear and there were reflections that made listening to them more like listening in a room. The V2 are more focused and the imaging is spot on, this is because now the sound is basically directly sent into your ear, as is the case with most headphones. I used to be fooled and have to check whether or not I accidently set my output to the LS50's on my desk. With the V2 I don't have that problem. I've encountered the situation only once with the V2, and it was when I was running crossfeed. I get the feeling most people enjoy the less-fuzzy, directness of the V2. I like it, but also sort of miss the uniqueness of the V1.
Frequency response: Mostly what I hear here is a difference in treble, and some other difference that may or may not be because of the soundstage change. I once commented that the treble was euphonic on the V1. With the V2 it's not as present. The V1's were unusable with my Hugo; they became too bright. With the V2's the treble is diminished on my Naim DAC-V1, but the Hugo seems to do a better job here. However, I think the Naim still wins on voices--not sure here. I really need to listen to the Hugo more to form a good opinion.
Maybe it's time I try a tube amp. I dunno, the Bryston has always given me all I needed, and I love the fact that they have a 20 year warranty.
Thanks for reading.