Having the Samsung Galaxy Watch 5 44mm for almost 4 weeks now, I think it's time to write some first comments-impressions.
Battery life: One of the "hot" topics that interests many. Personally, I easily get a day and a half with notifications on, heart rate monitoring, steps, stress, sleep tracking, etc... Usually, I charge it in the morning as soon as I wake up and in an hour at most it's ready to wear and start my day.
Calls: I have spoken a few times from the watch, call quality/sound is satisfactory. I could hear fine, they could hear me fine, without the person on the other end realizing that I was talking from the watch and not from my phone. Also, because some have asked me if you can make calls through viber/whatsapp, etc. You can answer a call through whatsapp and talk normally, but not on viber/messenger.
Messages: You have an application for "regular" SMS messages, where you can start a new conversation and see all your conversations. Message recording works fine in Greek and conversion to text, through the gboard app. In whatsapp/viber/messenger messages, you receive and respond normally (including voice), but you cannot start a new conversation.
Payments: Google Pay is supported normally, you can make your payments easily and quickly.
Measurements: Comparing with the previous amazfit GTR3/GTS3, it's not comparable, it's much better. Especially in heart rate monitoring, the others showed me even in relaxed walking, for example, 160 beats, this shows, for example, 100 or max 110 which is the reality. I also consider it reliable in step counting. I also observed to see if it counts steps when driving, fortunately it doesn't do anything like that (I have read in various reviews of other watches counting steps while driving, tragic).
WatchFaces: There are many watchfaces available on the playstore. The only "bad" thing is that most of them are available for a fee, however, there are applications that give daily coupons for free watchfaces or you may come across nice watchfaces with good discounts.
Weight/Durability: Personally, I find it very light and comfortable, almost not feeling that I am wearing it or just barely feeling it. I put a membrane on the screen and also got an extra case which I wear on special occasions, where it might get hit or scratched to be protected.
One negative I notice on the Samsung Galaxy Watch 5 is the vibration... Even in the "prolonged" and "strong" setting, it doesn't have much intensity. In calls while I was sleeping, I didn't wake up. I say this comparing, for example, the vibration on Amazfit GTR 2/GTR 3/GTS 3 which was more intense.