I really don’t like the new Watch OS.
I don’t like that you can’t swipe between watch faces anymore, or that you can turn the Digital Crown to enter night mode. Does anyone know if there are any settings to get around these (for me) problems?
At the moment, I’m not a fan of the Smart Stack, but that might change. Any tips on how to customise it?
Watch OS 10 is the first big redesign of the OS as far as I am concerned.
It definitely needs time to get used to it, but so far, I am quite impressed because WatchOS 10 does provide me with more options to control my watch in this small user interface. I like it. Smart stacks can become very powerful if the OS or third party developers are doing it right.
Regarding night mode:
I did not have the time to dive deeper into WatchOS 10. Maybe there is a setting turning off this automatic behavior? I have no idea.
EDIT:
I appreciate the change because I have changed the watch face inadvertently multiple times. 
The new way:
Touch and hold the watch face, swipe to the one you want, then tap it.
I quite like it. First update to make big changes across the board. Every app is more vibrant and useful and grown up feeling
I downloaded the beta about a week before the final OS came out. I hated it during the first few days but it’s grown on me a lot.
I didn’t originally like the remapping of the buttons, and I thought smart-stacks was poorly thought out and a feature I’d never use.
I’ve gotten used to it though, and a lot of third party developers (Carrot, Fantastical) have rewritten a lot of their UI to make things bigger and more grown up – as @SB-MacBook mentioned in an earlier post.
I find myself using smart stacks as a quick way to log a workout. I used to change to the “Activity” digital watch face whenever I would go for a run or walk the dog, but now I just use the crown and scroll to the bottom of the smart stack screen and there is my workout app.
I’ve actually forgotten about that! It threw me off for a while too, but now - second nature.
I think now they’ve dropped Series 3 and earlier with the smaller screen, they’re able to utilise the bigger space of the current and new/future models better 
Any new system is disorienting, but give it time. I purposely did not install the betas over the summer (first time ever going from old public to new public releases without installing the betas), and initially I was a bit lost. For the first 10 minutes or so using the watchOS upgrade I was just poking around, seeing what got moved where, and was baffled as to how to swipe between watch faces. By the way, I appreciate the change with that feature - do you know how many times you can accidentally switch watch faces by wearing a long-sleeved shirt prior to watchOS 10? (Hint: endless amounts).
I’m still waiting to see how much battery life has been traded for the fancy new graphics.
Does anyone know how to change the app in the Dock? I can’t find the setting anymore
AND,
reduce some those unnecessary transitions
This was my biggest complaint, but I got used to it.
I’m still charging an hour before bed every night, wearing it to track sleep, then when I wake up, putting it on for 15-20 mins as I shower (leather strap can’t do water) and I tend to make it to around 8pm. If I do a lot of activity tracking then it will start to get low around 6. I think my SE (bought April 2021) is just naturally decreasing, but I must admit, barely noticeable to me. If I get another year - I’ll replace it. Two years, and I’ll replace it with the Series 9 (11 by then) with the beautiful stainless steel edge
My red dot notification indicator doesn’t seem to want to go away, even when there are no notifications. I’ve tried turning it off/on in settings.
Anybody else seeing this bug?
I refuse to upgrade if I’ll lose the ability to swipe left and right for different faces. That’s my single most-used feature of the AW after the time itself.
It’s still very easy. Just press and swipe as before.
They have changed my beloved timers app 
I’m sure I will get used to the change, but I suspect I will have a frustrating few days as I figure out navigating the new menu.
It’s also probably going to be a frustrating few days not swiping up in order to set the water Lock Screen with wet fingers 
I’m trying to understand the reason Apple remove these gesture based triggers. Before, you swipe up for the Control Centre. Now, you press the button for it. Were there many cases of reported accidentals swipes that caused confusion when watch face change or control centre appears out of no where? Otherwise, why made such a drastic change?
Sad to say you are stuck then (at least for this OS upgrade). I think that’s a bummer reason to miss out on the other niceties of the OS this go around. And as others have pointed out, swapping only take a moment longer now than it did before.
I for one am glad I won’t accidentally change watch faces anymore
I happen to like the new watch OS. The rearrangement works well for me. I also have problems with the watch face accidentally switching, so the new interlock solves that problem.
I am enjoying most of the changes, but this is a huge disappointment to me, too. I know you can press and hold, but swiping was fast. I used faces as an app launcher of sorts, with commonly used apps in complications on faces to the left and right of my main face.
I am in love with the new Watch OS. Finally the watch is able to show data without digging into respective apps or multiple clicks in the weather app.
I have put up tons of widgets for Weather which were generally buried under the weather app. No longer I have to go clicking around in the weather app.
As a 55 year old guy who grew up reading every Peanuts book and watching every TV show and movie with my dad (passed in 2017 at 90 years of age), may I say I absolutely LOVE the Snoopy watch face 