My impressions are pretty much the same with the X3 as I heard with your tracks on my computer. Not sure why the Clip sounds like that with the NAD's. I'm going to verify what I heard today with it. I only had a quick 10 minute listen through the Clip today.
I know a few people here have said they prefer the 545's to the NAD's, but I'm leaning the other way. There really is something addictive with the NAD's. Not sure where you live and if you have access to amazon, but there is no risk to try them both through amazon and return one. If you have $550 to spare and can wait a couple or 3 weeks to get $250 or $300 refunded(depending on which one you return) try them both out. I know its a lot of money to have out there for a couple of weeks, but you don't want that nagging feeling that you made the wrong choice.
Edited by Painful Chafe - 2/22/14 at 9:28pm