For sure, Alien needs all tracks numbered 01,02,03 as well, makes a clicking sound between tracks like C3.
But when it puts out sound on par or above my DX90 at a fraction of the expense we deal with it. (all relates to my post above / what we're willing to accept in exchange for sound)
I think you've pretty much picked up the right idea. I can hear stronger instrument separation and wider soundstage with X2 over a Clip and the detail is about 10% 20% better, X2 also sounds a little cleaner overall to me a little more effortless and less congested. This is with mid-level hybrids and IEM like Brainwavs S5 (which I think is a very good IEM btw). But when moving up to a full-size headphone like SRH840 (even though low impedance) the Sansa unit could not drive 840 to a level my X2 can, notably the level of dynamics and driving authority.
Long as we remember X2 is $55, then we can keep the expectations in line.
Rather than look at players like they're 'better', I like to use the term 'different'.