Thanks.
May i also ask how many CIQ spots you can use (2 on the 235, not sure what the 6xx series offers)?
You'll see :) let me know. Dimensions are quoted by largest values, which is maybe only 0.5 mm in diameter, but overall edge is small.
The buttons on my 735 have a better feel. They're still plastic like the 235's, but they have a more solid feel to them. It could be due to age of the watch – I had the 235 since last November – or just manufacturing variations, but the 735 buttons feel slightly better to me.
FWIW i just replaced my December-purchased 235 with a new one this month and i noticed a distinct difference in the buttons. A little more solid with a distinct click when pressing them. So this might be a manufacturing refinement in the general construction process of the new FR watches.