I'll add my vote as another impressed Iconoclast customer. While I've always thought that cables can make a positive impact on system SQ, I've rarely felt that the price of more-expensive cables was worth it relative to other equipment upgrades.
My current system requires fairly lengthy 7M balanced cables between my preamp and monoblock power amps. I tried several different cables - mostly DIY since it's hard to trial long cables - and wasn't complete satisfied. They all sounded a bit different, and I felt if I could combine the best characteristics of each, I'd be golden.
Iconoclast was one of the few companies that offered a home-trial even for custom lengths. That combined with their detailed explanations of design philosophy and construction specifics convinced me to give them a try. Also, these cables were pretty pricey, but not as bad as other premium cables for long lengths.
Well, they far exceeded my expectations. I don't think I've ever done a cable swap where the improvement was as immediate and significant. Sometimes a new component upgrade sounds great on first install, but after listening for a while you start to hear the flaws. Not the case here. I'm liking my system more and more then longer I've had these.
I still have one other analog interconnect in my system (DAC to Pre) that I plan to upgrade, and I want to give the Icononclast speaker cables a try as well. I never thought I'd be spending this kind of money on cables, but IMO, these are well worth it.
Everyone says that you have to match the cable to the system. I'm sure there is some truth to that, and it's possible that this is what is happening here, but I think it may just be that a really well designed and manufactured cable will improve almost any resolving system.