I may not have been at my most critical or may not have chosen the best music for comparisons, but I didn't feel there was that big a gap between my 5LEs and the 6 and 500s when I compared them on the same amps at the ChiUniFi meetup last week. Also heard the LCD-2, and they also failed to tempt me.
*phew* I was releived not to be tempted by an upgrade.
Though it must be said that al sounded fantastic.