HEK's are a neutral headphone, takes a while to get used to anything else after being used the Abyss, my 1st response with the HEK was where's the bass, its there okay, actually I think its more extended than the Abyss and certainly has more detail & texture. I realised later that in contrast the Abyss imprints its bass signature on everything, its not as accurate. When I listen to some large scale orchestral pieces and some soundtracks (Hans Zimmer - Inception etc) I realised that there is plenty of bass extension there alright, but its more accurately proportioned within the music. The Abyss bass can be quite a party trick.
No doubt the HEK is higher resolution. Took me a few days for my ears to re-adjust. The HEK scales very well, and is accurate to the source, have run it with different DAC's and it reveals and rewards the better equipment.
Also received the DHC Spore4 Silver yesterday, quite different to what I was expecting being Silver I thought it would be brighter, not so, big upgrade over the stock cable. Lovely texture and harmonic richness to the sound whilst being open and transparent. Suits the HEK well and lifts it to a new level ( as one would hope given the $)