I have just used Galaxy Watch 4 Classic LTE for a single day and there exists so many issues. I just feel like returning the product.
First and known battery drain issue almost 1% battery drain every 2-4 minutes of use which can be controlled if I turn off health trackers and mobile networks.
Then formatting watch takes a whole lot of time and connection to another phone also takes a lot of time I guess it should be simple and does not always have to reset everything on watch and connect again to a new device.
Major issue: I have tried connecting this watch to different phones Nokia 9 & Vivo V20 Pro and tried if Call on Earbuds work correctly or not. Now I have connected watch to my phone and my Bose earbuds are connected to the watch. Luckily I don't have Samsung earbuds because I can't bear with simple problems which should have been fixed until now. Samsung wants to release Galaxy Watch 5 and there exists so many issues in old watch. Great!!!
Now when I call on the phone which is connected to the watch I am unable to hear anything on earbuds, the sound always comes from a watch and there is just a button to pick a call on phone, whereas there should be 2 buttons pick a call on phone and pick a call on connected earbuds it's so easy I guess. Then the sound coming out of watch is echoing multiple times and it's just annoying. Apart from this the person I am talking to is also getting this echo. Sometimes watch only connects to one earbud and there is no sound from other earbud until I play next song on Spotify, apart from that song playback works ok.
Since Samsung has one ui, Google wear os apps are not supported and Samsung app does not have that much flexibility in terms of watch settings and apps.