I have connected a Kubala Sosna Elation, and an Emotion to the Puritan 156 with good results.
I have also used a BMI Whale Elite, an Elrod EPS2 and 3, an NRG Godzilla 5 is on there now, and some Harmonix and Hijiri's to the front of the Puritan.
The Harmonix and Hijiri's slightly restricted the sound. The Whales were very good and I still have 2 on the rack.
I did not try the Sablon or Masterbuilt on the very front end.
The standard Puritan cable is not bad at all. But when you're upgrading all around the downstream components, letting the electrons flow at the wall is a good idea.
Overall, I only experienced slight downgrades, very slight, so the majority of PC's did very well in front of the Puritan. Not sure what might be going on with the Shunyatas. Don't have any and don't plan to any time soon. The NRG works darned nice btw.
My 2 cents.