I bet the Anal-yst is wrong.

Until about a year ago, I was happy with my trusty old S3. 720p felt good enough @4.8", which also felt big enough. Speed still felt fine (not a gamer). Camera was OK for a portable (I prefer a real camera anyways). I say we hit the smartphone sweet spot years ago. Carwise, the Galaxy S3 is the original '64 Porsche 911, it improving on the iconic Porsche 356 (iPhone 1). The new iPhone/S8 would be the 2017 911, with the '64 original still showing it's influence, even now. These days, I really like Motorola phones. Bought 4 in the last year. (G (2nd), X Pure, Z Play) Feel solid, they run pure android like Nexus and have fantastic battery life. The Z Play has Epic battery life (beats all those charted above) and lightning fast charging. Don't look past Motorola, especially in the $300-450 range.

The only downside to Motorola, is that they're owned by Lenovo.... Considering their piss-poor support in the consumer PC market, I have little faith in their support for smartphones.

I would say iPhone vs Samsung (iOS vs Android) are two completely separate markets other than a small handful of people who think the grass is greener and switch for a test I can't see Android users all suddenly moving to iOS because of a new iPhone, not to the point it would make any noticeable impact on S8 sales Nor can I see the opposite happening

This! It's not like Android users are unaware that Apple exists (though it may be so the other way around). As you said, users have chosen their sides. What could happen is that some Apple users are in a spot where they feel they cannot afford another Apple and therefore move to the mid Android segment. On the other hand it could work the opposite way too.