It's not a 1/3" sensor as we see on so many other phones - it's 1/2.6" - that means more area to gather more light - that's a step up.
And the pixels are not 1.1Ám on a side, they're 1.4Ám.
That's 60% more light per pixel than a 1.1Ám.
Outside the HTC One with is its 2Ám/side pixels, 1.4Ám has been fairly standard, and as the megapixels went up on most cameras, the size went down.
Here, they've increased the sensor size.
Much better than anything mentioned earlier about this camera.
Once again - not last year's tech.
AnandTech | A Quick Look at the Moto X - Motorola's New Flagship - Print View
Proof will only come in the final results - with decent software.