The "Holy Grail Phone" for me isn't an S4 running stock Android OR an HTC One running stock Android
First off: I think it's awesome that Google is releasing an S4 running stock Android. Good on them - great software with great, inlocked hardware. I'm a very, very satisfied HTC One owner, but that doesn't make this any less cool.
That said - for me, the "Holy Grail Phone" isn't the Google Edition Galaxy S4, or even a hypothetical Google Edition HTC One. While I do prefer stock Android to Sense 5 and TouchWiz, there's one thing on both those skins that blows away stock Android - the camera functionality.
Give me an S4 or an HTC One running stock Android but with the OEM camera functionality, then I will throw all of the money at you. The additional camera functionality provided by both OEMs blows away stock Android's functionality, to the point where I'd rather put up with Sense or TouchWiz, then lose those added benefits.
Of course, that's just me - I love using the camera on my phone to capture and share moments, so anything that makes that easier is a big deal to me. What do you guys think - is stock Android worth losing all of those camera features? Do you value software experience over camera functionality? Or would you rather see a hybrid solution?