I've had my 935 for a few days now (to replace a borked F3 I don't have time to fix. On the plus side, it's a surprisingly nice upgrade!). One thing I notice is that, with the altimeter in Auto mode, the altimeter doesn't seem to track even relatively fast changes at all. Like, if I go down the stairs, the altitude stays right where it is and doesn't notice the sudden 10' change. This is coupled, of course, with a general failure to count flights of stairs - I might take 30 in a day, but only see 3-5 on the watch. I do usually take two steps at a time, so perhaps that's throwing it off? But it seems like that should still be easy enough to algorithmically classify as a staircase, at least for full flights. If I fix the altimeter mode to "Altimeter", the problem seems to go away (tough to test, since the watch seems to filter out rapid up/down/up/down), both in the altimeter reactivity (as one would expect) and in the steps counting (also as I'd expect). But in Auto mode, it seems never to get the memo that I'm moving, even if I'm moving pretty aggressively.
What's also odd is, with the watch left in Auto, the altimeter seems to remain quite accurate over the long term; it seems to always be within 10 feet or so of actual reference elevation as checked against a map source. Which is to say, it doesn't seem to be missing the staircases as altitude events rather than pressure changes, it must be counting them. But if so, why doesn't it seem to keep up in the short term?
FWIW, in Auto mode, as soon as I get in the car, altitude starts reacting pretty much immediately.
