RCA vs XLR

You need to find a new dealer.

Elgordo is right. Find a new dealer. What a joke...............................
"RCA connections will tend to sound more 3 dimensional that XLR".
I will put this on the top 10 list of the dumbest things we've ever heard a dealer say.
If people wonder why so many (hifi) consumers are so confused there is a prime example (dumb dishonest & usually disorganized dealers).
Yes, Avguygeorge, we find that TRUE balance usually (not always) sounds best, but many components aren't balanced, they just have XLR's (FYI for Jeffmazen).

Yeah, right. RCAs sound better than XLRs. That one ranks right up there with Pioneer's claim in the late 70s that their engineers had developed a tonearm that was lighter in weight but higher in mass. Maybe all the recording studios and broadcasting facilities in the world have missed the boat, and should immediately switch to using RCA connectors on all their cables. Now we finally know why recordings never, ever really sound like live music. It's those damned XLR connectors on the microphone cables.

Sounds like you ran across one of those people who think Single Ended is the only way to do audio. I am in total agreement with the fact that this guy is wrong -- how can RCA image better when XLR typically has 3-6 dB lower noise floor as compared to RCA???

Ideally, neither XLR or RCA plugs should have a characteristic "sound". Pro audio types use XLR because of its relative immunity to RF contamination and its locking connection. In a low RF environment it's possible that single-ended RCA connections may sound better than balanced XLRs. This is due to the fact that truly balanced equipment requires a much more complex circuit design and implementation. In other words, it's easier to screw up a balanced design than a single-ended component. That's in theory, in practice it may be just the opposite. I use balanced XLRs, but then again I live in a high RF area. Your dealer is at the very least overly simplifying the issue.