Ha - In fact I pre-ordered both (F5S and F5) just to see what size fits me best. I would guess the F5S? But then exactly as others are stating, the F5 clearly looks smaller than F3.
Time will tell...
Well shucks. I was pretty much decided on the F5S thinking that the size difference between the F3/F5X and the F5 wasn't great enough. These photos has me rethinking that not only because of the size but because it looks like the display is much better which my aging eyes will really appreciate.
Your 735XT is nearly identical in size to the 5S... the 5S is 1mm smaller in diameter (43 vs 42) but the 5S is significantly thicker. When I had the 235 I certainly felt it was a "man's" watch in terms of diameter and the 5S should pretty much be similar but thicker and heavier.
What is the meaning of trends?
PS: Just asked Ray Maker (who has a 5, 5S and 5X in his hands) about these photos and he says there is no tangible difference in clarity / contrast between any of the three models and that he feels the photos on that site seem edited somewhat and that the difference between all the fenix 5 models and the fenix 3 isn't quite as significant as the photos make them look.
In this context of this specific conversation, it was referring to the new "Training Status" levels. For example, at the moment it says my training status is 'Productive', my fitness is 'Increasing' (Up Arrow icon), and my load is staying constant (side arrow icon). It's also inclusive of the training recommendations based on load. For right now it's telling me I have 23 hours of recovery, but notably to 'Train as usual'.
Further, my Training Load in the last 7 days is '942' and considered 'Optimal' for me.
And it's really the 'for me' part here is what's important, and why it takes a few weeks to identify those trends.
As for more clarity/detail on all of this...yup, working on it. Meeting again with FirstBeat folks tomorrow for a few more hours of 'education' on it all (following a few hours I spent with them at CES). This is to go through the final variant of their algorithm packages as included in the Fenix5 (which may have differed slightly from what things looked like in early January).
If I have some spare time tomorrow afternoon (it's a show day at MWC), I'll find a spot to shoot side by side video on the two (I brought a F3 with me), so there's no real issue of photo tweaking. Certainly the Fenix5 has more pixels, but in terms of readability, not seeing it being all that tangibly different (something even Garmin themselves also has stated).