Cables
I’ve never heard the Bolder ICs, but I have heard the Cardas NR in several systems (including my own) and I own the Gedes. In the systems I have heard the Cardas and the Gede, the Cardas was nearly better in nearly every way - even in my own. I think the one area where the Gede was superior was in my enjoyment of the music. In my testing of various ICs I simply enjoyed the music better in that particular system (the NAD 521BEE & 320BEE) even though I acknowledged the Cardas’ superiority in nearly every arena. However, in my dad's higher-resolution systems and my own mid-fi vinyl rig, the Cardas NR simply allowed more of the music to be heard. The comparison is not quite fair because the Gede's can be had for $100 new (through Zu's eBay store) and the Cardas NR are quite a bit more. I think a more fair comparison is between the Zu Varial and the Cardas NR, as both have similar prices and really perform n par with each other in many ways (I prefer the Varial for my vinyl rig, but I would choose the Cardas NR for my dad’s analog rig – which currently has the VD Masters). In the end, like any audio component, the answer depends on your system and your tastes; this means only you can answer this question. The simple answer is that in most systems the Cardas will probably sound better than the Zu Gede because it's simply in another class of performance. Always consider your personal sound preferences and never underestimate the power of synergy.