5ATM - Waterproofness

It is also rather difficult for any of us to comment on long term durability on a product that isn't even yet in widespread availability.

As as aside, a lot of people wonder if the plastic buttons on Forerunners are not "durable" and yet they don't seem to fail in general.

Furthermore, waterproof rating is only one aspect of durability. And since there are very few proven reports of devices directly failing as a consequence of water ingress I would suggest that you look at other aspects of the device specifications to assuage your quest for any assurances concerning durability.

If the barometer was the only thing that failed on your watches, then it is clearly NOT a waterproofing issue. The barometer sensor is exposed to the outside environment.

Not the electrical connections. They need to remain waterproof. That's why waterproofing a barometer is likely to be hard - you have to allow air (and therefore usually water) access to part of it without allowing access to the bits that can't tolerate water.

But as i said, the question is one of general durability and whether there's a difference. That's only likely to be answered by time, a garmin insider, or someone who's done a teardown.

Anyway, there's been far too much argument about whether we're allowed to ask the question without anyone actually even attempting to answer it - or even the simple "what does the box say?" from the first post. I'm going to give up posting to try to justify why I'm interested in this, but will remain interested (and will respond) if anyone with useful information wants to post here.

but will remain interested (and will respond) if anyone with useful information wants to post here.

The problem is that nobody knows what information you will find useful. Garmin says the watch is rated 5ATM and that it is good for swimming (and this answer has been given before), and yet you insist that it is not. So again - what is your question?

The original point seemed to be "I'm interested in the 935 but concerned about longevity"

But as also mentioned us speculating about longevity for a product that only a few people have had for a few weeks is largely total guesswork. That said mine is still working!

… without anyone actually even attempting to answer it - or even the simple "what does the box say?" from the first post.

That only proves you aren't taking in what others have written. From post #4 in this thread,

Box says 5 ATM,

I recently have been diving with my 935 down to 80 feet, or less than 3ATM’s with no issues. 5ATMS is over 150ft which is beyond open water or rec diving limits.

Just because you can doesn't mean you should. Don't go complaining to Garmin if it breaks.