I used this smartwatch for 2 months before writing this review. I'm a mountain biker and I've been using heart rate monitors for years, mostly the Polar line of watches and chest straps. A few years back I decided to try the first Fitbit Versa, as I wanted to see if a smartwatch could work as a good heart rate monitor during workouts as well. That Versa didn't work, the heart rate was inaccurate and all over the place, so I just kept using my Polar accessories, until this new Fitbit Versa 3 came along.I have tried this Fitbit Versa 3 on rides outdoors and on Spinning sessions indoors, and this is what I've experienced:- Outdoor rides: the GPS works almost flawlessly, the signal gets lost in the woods and around large buildings and large hills, but it comes back to normal quickly. The interface is gorgeous, clean, clear, easy to read, easy to handle during rides, fantastic in general but there's just one big problem, no matter how beautiful and easy to use is this, the heart rate monitor doesn't work. I ride on the same hilly areas all the time, I know how my heart rate behaves in certain hills and roads, up certain steep hills it gets all the way up to 200 bpm, but this watch NEVER once showed that number, it gets to 175 bpm and then it goes blank, the reader cannot handle a faster heart rate, it just goes crazy and stops working, then as I'm climbing the end of the hill it shows a 120 bpm number, which is the heart rate I get when I'm casually walking. Completely inaccurate and all over the place. The maximum heart rate this watch has read during my rides in 2 months is 176 bpm after an uphill that usually makes my heart go up to 200 bpm. After many times of bad readings, I tried both my Polar Ignite and this Versa 3 at the same time during my rides, and the difference was outstanding, the Polar (without a chest strap) was giving me all the right readings flawlessly while the Versa 3 was blank or inaccurate or all over place. All the same problems happened during my running and hiking workouts.- Spinning sessions: during Spinning sessions my heart goes up to 196/ 200 bpm, the Fitbit Versa again got stuck at 170/ 175 bpm and then went blank, and it was giving me bad readings the whole session, always below my actual heart rate, therefore messing up my stats and saying that I burnt a LOT less calories than I actually do. In the photo I'm attaching the Polar Ignite (left) shows my real heart rate and calories burnt during a workout, while the Versa 3 (right) shows the wrong heart rate and the wrong calories burnt, if you see the numbers, they are completely different. I've used this watch for 2 months and tried everything to make it work, all troubleshooting options , but nothing made the heart rate reader work properly.If you take your workouts and stats half-serious, this is not the watch for you, it works fine during casual workouts, like walking or gardening or doing light exercises that won't take your heart over the 180 bpm threshold, once you are higher that that the Versa 3 goes berserk, it cannot read anything faster than that.I'm sticking with my chunky, not-too-cool Polar watches, they may not look as beautiful as the Fitbit products, but they are hard working and completely accurate when it comes to tracking my heart rate, workouts and sports.After wearing this Fitbit Versa 3 smartwatch for 2 months:- The good: AMAZING battery life, about a week or so depending on your settings, beautiful interface, not many apps to use but enough for my usage, as I prefer to use my cellphone for apps in general, light and comfortable to wear, the new strap is cool and comfy, good to track steps, stairs and regular day long activity.Good and accurate GPS without the need for a cellphone. I never used the Alexa option so I cannot comment on that. I tried to respond to my text messages with the voice/dictation option (the watch has a microphone) and didn't work, it may be because I have an accent, who knows, but I think that option is pretty cool. FANTASTIC cellphone app to handle all your info and data.- The bad: AWFUL as a heart rate monitor, awful at sleep tracking, according to this watch I'm a zombie who sleeps 2 hours and has no heartbeat the rest of the night, some nights it won't even track one minute. Yes, I've tried wearing it higher or lower on my wrists, the left one and the right one, none of that made a difference.I hope that at some point Fitbit gets the right technology to make the heart rate reading sensors accurate (like other brands have already done), that'd make it an almost perfect smart watch and real activity tracker. I wish them the best, they are doing a great work with most of their products and one can see the effort and love they put on the things they create, except the damn heart rate sensors! ;)