Single Ened or Balanced Pass Labs

Just reading a couple of threads hear on the Gon, got me thinking, I have always used Balanced conection with my PASS x350.5 and for that matter my last Krell intergrated, all my gear realy! I have been looking for a new set of cables for between my MSB Dac and my power amp there seems to be more RCA about for sale and they are cheaper due to contruction of course compare to there cousins, are there any other's Pass labs owners out there that can shed some light on this, will I notice the differance, I would only be running very short runs .600mm min , I will check my stash of old cables tomorrow for some RCA and give them ago, reading the manual, these amps are design well with regards to rejecting noise and what ever else, which is good to read, Pass manual said they tested lots of different cables and it came down to conection of the cable, more than the design of the cable and that you should not spend more on the cable then amp it self (I like that part the best!)I currently using a Sealth Sexist Digital cable (Balance) and alway dream of trying a pair Indra's but I can't justfy the cost of a balanced pair!as I was told they where a must with the MSB
Whats your thoughts?
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I owned the X600 and called Pass Labs with the same question (SE / Balanced). Incredibly, non other than Mr. Pass himself answered!

His answer was (to the best of my memory): "...these amps were not meant to be run SE" and "...will not perform up to their full potential."

Bugger me!Looks like Iam going to have to harvest another organ, are they realy that good , the Indra's, what a resonable price second hand to offer someone?