10.4 is the thickest, tapering out to I think 4mm. If you hold one in your hand I think you'd find that 10.4mm doesn't mean anything when it comes to comfort.. I'm going to guess that many would find MotoX design more comfortable than even Apple's new iPhone 6. It feels a lot smaller than it actually is. I do like the changes Apple made tho and it too will probably feel smaller than a typical 4.7" phone. Smoothing those edges is a good move.