XLR vs RCA

I recently purchased a new Streamer/Pre/Dac (Linn ADSM/3 w/Katalyst) and a PS Audio S300 power amp.  I hooked them up using some high-end RCA cables and they sounded great.  After doing a little reading and from advice for PS Audio I orders some XLR cables (Mogami).  They are decent but not overly expensive cables.  They arrived today so I got it all changed over.  I gotta say it is a significant difference.  I realize they have a higher gain, but I am amazed about the change in the soundstage.  It just blossomed.  One of my favorite albums is Aaron Neville - The Soul Classics.  I have played this hundreds of times, so I am very familiar with it.  Today I heard in a whole different light.  Awesome.