Yeah I'll bite. Cables make almost no difference at all if their electrical properties are similar. Any perceived benefits are 100% placebo.
In double blind tests NOBODY has ever been able to establish a success rate of anything other than what you'd expect from chance. I used to buy into cables until I tried tricky speaker cables on dem. Between a very well respected amp (Lavardin IT) and some eletrostatics (Martin Logan) a system easily capable of showing any change there was absolutely no difference between a 1k cable and the 2 quid a meter (because it looks nice and some is on show) stuff I now use.
Naim especially ought to be ashamed of themselves, they sell the fact that all of their gear benefits greatly from additional power supplies, the sheer neck of suggesting that the last three feet of mains coming into these supplies would make a difference is almost beyond belief.
Also the dealer gave you 420 quids worth of mains, no, the dealer gave you a 20 quid mains lead priced at 420 quid.
Also Russ Andrews the snake oil king has been forced to amend all his ads and descriptions to add in the phrase "in our opinion" because the ASA took him to task over his nonsense.
Love the Uniti, good choice..