Since you brought the Amp3 into the discussion, just as a comparison ... using specs from Amazon and the Amp3 maker's site.
Sony X1000 = 0.4 x 2.1 x 3.9 inches ; 5.6 ounces
Amp3 = 0.78 x 1.6 x 2.9 inches; 3.5 ounces
Leaving web browsing out of the mix (since thread is about best sounding Sony), the Sony crushes the Amp3 with its screen and menu, as well as options like EQ, etc. The Amp3 offers expandability using MicroSDHC cards (but only 8GB at a time, right now, so the basic config is 12GB for about $170, while the Sony 16GB model is $297 at Amazon). Both play wma, mp3 and wav, but the Amp3 apparently also plays Flac, but only using onboard flash memory (not the cards). The Amp3 also can be used as an external amp with another DAP, and has a rated battery life of 100 hours per charge (not sure about the Sony). There is no onboard EQ on the Amp3, by design.
As far as SQ, only one person has both that I know of, and he says the Amp3 delivers superior SQ (though he does sell the Amp3, so more data is needed). I would love to do a comparison, but have opted for the Amp3 for cost and expandability/flexibility reasons (I can probably sell my T4 if this amp equals it with other DAPs).
Of course, the Sony clearly wins the overall features/beauty contest. But the amp3, while a bit thicker (and it does have those jagged edges), is actually smaller and lighter.
And yes, it's nice to have choices in audiophile DAPs.