I have the LS50's paired with Audio Research VSi55 I got for 1830 on audiogon. They are an amazing match. I don't think I could do much better. I keep on thinking of ways to change/upgrading the integrated but just in the end don't want to loose the synergy of this setup, its phenomenal, even despite being set up in a fairly large room with 9 foot ceilings.
If I had a balanced source I would like to compare it to a Ayre Ax-7e someday...
Entry level Transparent cabling and a Bluesound Vault as a source using the on board DAC. Soon to be switch to a Auralic Aries Mini.
Sam