The X3 mk II was my first FiiO DAP! I liked almost everything about it, except no Bluetooth (which didn’t matter because I had no Bluetooth device at the time) and the scroll wheel was nowhere near as responsive as Apple’s (which had spoiled me).
Both versions of the KANN are amazing. Bit out of my price range, but even price-no-object they are too big to fit into a pocket and thus I would have a hard time making practical use of them :( Still, I got to spend some hands-on, no crowds time to privately listen to the original KANN, and I can definitely say Astell & Kern know how to make a fine sounding player!
I’m actually having a hard time choosing now between my Sony ZX300A and my FiiO X7. I thought I was going to love the Sony battery life and sound quality, and those features are impressive... but honestly the battery life hasn’t come into play for the Sony (even when I took it to CanJam SoCal this year!), and the Sony’s sound quality is different rather than better... great detail and texture in the Sony, but it doesn’t have the grunt and fullness of the X7. Biggest “hrmmm...” with the Sony is it doesn’t want to see or connect to my car Wirelessly, and my car’s wired line-input gets really bad channel imbalance that switches around while I’m driving (even the digital wired input has this issue, so I have to use Bluetooth).