Today my Not-Quite-Black Pixel arrived, and I have it side by side with my S7 (work phone).
Some hardware impressions:
-From pictures, the bottom bezel didn't seem too bad. However with the phone in front of me my first impression was, "dang that bezel is huge". I'm starting to get used to it, but on the Moto X the bottom bezel was much smaller than the top to balance out the on-screen buttons, which resulted in pleasing proportions, which the Pixel doesn't have. I agree with criticisms here.
-People have called the Pixel plain. I can see where they're coming from, but to me it's not an unattractive phone. If it had smaller bezels I might even give it praise. It's nowhere near perfect, but I like the minimalist slant.
-Even though the Pixel is smaller in the 2 dimensions that matter most to usability, and lighter, the S7 has the illusion of being a smaller phone (for me) due to it's smaller height. That said, I do slightly prefer the size and shape of the pixel in-hand.
-I like the fingerprint scanner's location on the S7 better. The Pixel's isn't in a location where my finger rests naturally so I'm probably not going to use it.
-The Pixel's buttons are a bit more clicky than the S7's. They don't feel "cheap" exactly, but the S7 gives more of an impression of solidity.
-The aluminum back on the Pixel is much colder when you live in the great white north. However, I generally prefer the aluminum and would've been fine had the whole back of the phone been metal.
-I'm left-handed and prefer the Pixel's navigation button layout.
-The screens on both phones look about the same to me, both in color reproduction and crispness. I dunno why Samsung put so many pixels in a 5.1" screen, I'm sure a 1080P screen would have resulted in better battery life and performance (all else being equal).
-Both phones have very nice cameras. I have no complaints about either, and neither is clearly better or worse than the other without scrutiny.
-The speakers on both are in similar places (opposite sides) and sound similar.
-The Type-C connector feels a lot more solid than microUSB. I just need to update my cable collection.
Software impressions:
-Vanilla 7.1 definitely wins vs TW 6.0.1 for me. As with the hardware, the software seems more minimalist, with less visual clutter, without losing any functionality I care about.
-The Pixel is fast. It's noticeably faster than the S7 in just about everything.
-I like the Pixel's launcher a lot more than Samsung's stock launcher. I know this can easily be changed, but I'm using the stock launcher on both phones.
-As silly as it sounds, I like Google's collection of random noises, notifications and ringtones much better than Samsung's. This can be changed too, of course.
-Google Assistant is pretty slick. This might be the first phone I actually use the voice commands with.
-The main reason I got the Pixel was for Google Fi, which has also been really slick so far. I live near the Canadian border and most phones have terrible service around here even when they're on US towers. Fi's multiple networks are exactly what I needed, and there is no Samsung option for that (yet).
At the end of day one, I like the Pixel better. If I were given both an S7 and Pixel with freedom to choose any network on either, I'd still take the Pixel as my DD.