I'm thinking of going that way. Really curious how you would describe the improved SQ . . . massive, excellent, very good, good, above average, average, so so, eh. ???
Here are my thoughts on SQ:
Bass - sounds tighter and more accurate so I dialed up from 10:30 to 12 to increase bass quantity. May even crank this up more.
Mids - biggest difference was mids, as noted it was a bit dark sounding before and now very clear.
Treble - here I can be more specific. I think the increase in treble is 1-2 dB in the 4K and up range from just the cable. This is based on where I had EQ set before and now I don't need EQ at all. My recent FW upgrade of my RWAK240 helped a little bit on this as well.
Keep in mind that the improvements in mids and bass also had a lot to do with changing from foam tips to Spinfits. Unfortunately, I can't A/B with the foams because I can no longer get a tight seal with the same foam tips due to the change in ear hook design. However, I will say that given how fit is so important to the Laylas, the fixed ear hook design is far superior to the bendable wires imho. The Laylas are much more secure in my ears and I can move my head to the extremes and they don't move or change sound. Back with the foams, if I bend my neck too far looking down, treble starts getting muted. I think this is an important part of deciding on upgrading the cable.
One tip I can share is to consider a longer length of the y split. This is a heavy cable and you may want to clip it to your shirt to help with the weight and a longer y split length would be more comfortable. I personally don't walk around with my portable setup so not really an issue for me.