Is a balanced XLR cable inherently less critical than a single ended RCA one?

Nothing is a different story. Except that with balanced you're paying a whole lot more for nothing in return. Aside from that though anyone says any cable anywhere isn't important is blowing smoke up your, ... well let's just say they're blowing smoke.

If you have properly designed balanced electronics, I completely disagree with millercarbon. Google "pints with Ayre" to hear the reasons they go to a lot of trouble to design their equipment as balanced. Mogami balanced cables are used in recording studios for a reason. Spend your $$ elsewhere.

@tvad .
I have to say my experience mimics yours. I had some XLR's from Ralph Karsten that I have been using for years, but went with some new AQ XLR cables ( I have found their new cables work extremely well with my systems).
And, to be honest, I do not find a significant difference in sound quality. Which leads me to concur with Ralph, that XLR cables are inherently immune from coloring sound reproduction. To be fair, my system isn't set up in the best configuration. When I get my new subs, I will have my dealer do his best to optimise with what I have, and if it results in better sound quality, I will post accordingly.
Bob

As long as source and the input are not ground related capacitance between wire and shield has no effect, but capacitance between wires still exists.  Dielectric with lower dielectric constant will reduce capacitance between wires.  Signal wires in XLR are usually twisted - a very effective way of reducing electrical noise pickup, but nothing is 100%.  Better cables often have better shields protecting better.

Mike, I used Mogamis between my Coincident CSL preamp and my M-60's.  I changed the room a bit and I needed a longer pair ~30 ft, and couldn't get what I wanted from Mogami.   I bought a pair of Signal Cable Silver XLRs at about 5 x the cost of the Mogamis I had previously used.   They made a nice difference, but my guess is that you would not get any benefit if you were going from an MP-3 to M-60's.  You might hear a difference going from your TT to your Mp-3, but you might not.  BTW, VH audio also makes some nice balanced cables, but they are a good bit more expensive.   If you don't need a long length to go from your TT to your preamp, it might be worth trying the Signal cable silvers.  If you don't hear a difference, you haven't lost much.

I have 25' runs of balanced interconnect between preamplifier and amplifier.  I tried three different pairs.  They all sound different.  One was best.  For me it was NOS Discovery Cable.

I heard significant changes for the better when I switched from Mogami Gold XLRs to something else.

It all depends. When I upgraded my preamp to an ARC Ref 6 and my amp to an ARC 150SE, I tried five or six different XLR’s from Mogami up to Cardas Clear Beyond and they all sounded quite different. Morrow MA6 was the worst sounding, the Mogami was second worst, I can no longer recall what else I tried but there were several loaned to me at various price points and the Cardas sounded "right" immediately.
I never doubt Ralph Karsten’s technical knowledge or his statements about his own gear. But you can not paint broad swaths as to all gear. ARC warns their customer on the first page of the manuals to the above pieces to buy the very best balanced cable the customer can afford. After reading the views on this Board I bought the Mogami Golds and really wanted to believe that with balanced it would not matter. I had already spent my last discretionary dollar on the amp and preamp at the time. So there is no doubt in my mind that my impression is not due to ARC’s statement-I was biased in the opposite direction. So I will say it again-it all depends.
I am having a new bespoke built DAC assembled by Slawa Roshkow of SW1X that is true balanced, his DAC III Balanced. Dr. Roshkow says that despite being true balanced, he thinks. it sounds best run SE and that running balanced is only best for long runs. But-he says it still sounds far better than the non-balanced version of the same DAC because with this particular piece, the output transformers and related circuits resemble an amplifier and pass the output signal far better than using capacitors in place of the transformers (if I understand him correctly).

This guy lied balanced is always better there will be a bigger difference when you get some real cables.Have fun!!

Yes, balanced cables do make a difference. And, each one has its own signature sound. As you progress up the ladder of better and more sensitive equipment the differences in cable is apparent.

ozzy

This guy lied balanced is always better there will be a bigger difference when you get some real cables.Have fun!!

Are you referring to my story and Dr. Roshkow? if so, c'mon. No need to be calling people liars in this hobby of subjective "truths". What makes you think my SE cables are not top flight. They are. 
If you are responding to the OP, nevermind. 

I was responding to the OP. All I can relate to is my cable journey.

ozzy

IME with SE cables, they do make a big difference. It is not a stretch to say that the change in sound is akin to upgrading any component. I think I will invest in about a $1K used XLR cable.
Don’t think I would hear any big change with a less expensive one.

I have a Cerious Matrix (3M) balanced cable that I am thinking of putting up for sale within your price range. If you would be interested send me a PM.

ozzy