I chose the Versa to replace an older basic watch that had gotten scratched and dinged up so badly it wasn't readable any more; figured I'd give Fitbit another chance. And so far, I'm very pleased with the choice.As a watch, well, it tells time and date. It can give text and email notifications, though they're often delayed several seconds (but that's okay). The main reason to go for this watch is its activity tracking functions, and here it seems to be doing a great job so far. It even survives trips to the pool and my son's bathtime.What I found most surprising, though, is that simply having my activity readout visible and having goals for the various categories makes me want to hit them. I had a hybrid car for a while and that was bad--a car with an efficiency readout is a cruel thing to give to an engineer--but this doesn't make me obsess like hitting mileage numbers did. My Versa has spurred me to start taking walks at lunch every day to at least get some exercise during a 12-hour desk job day. It reminds me to get up and stretch my legs when I've been staring at difficult problems for a while. It tracks my workouts and gives me heart rate plots (very interesting, those) and I can see measurable changes in resting heart rate as I've started exercising more.Initially I was a little skeptical of the sleep phase tracking, but seeing the graph in the morning and correlating with how rested I feel and what I remember of waking up and dreaming, it seems reasonably close.I was also skeptical of the calorie tracking feature, figuring it was really overestimating. There was no way I was burning 3500+ calories a day with just a walk, as I hadn't been gaining or losing weight. But then on a whim, I tried out the food tracking part with some of the things I eat regularly. To my utter dismay, I found that I was indeed probably burning about that much, because apparently I'd been eating that much (insert eyes the size of dinner plates here).I do wish the battery life was better, though I charge it every night anyway. I also wish the charger wasn't so bulky, but I don't really see an alternative that doesn't involve an opening in the case. And sometimes it doesn't really recognize the wrist-flick to see the time without hitting buttons or tapping the screen.My biggest gripe is with the app; even with all-day sync turned off and "background data" disabled in Android it will still try to pull several megs a day of mobile data. Not cool when you share a 2GB plan with your wife. I had to get a firewall program for my (rooted) phone and completely block the app from using mobile data, so now it only syncs on wifi. The food tracking interface could use some minor improvements too.Overall, I'm extremely pleased and am trying to convince my wife to get one of these vs. a less-capable tracker.----------UPDATE 1/28/19: I'm still extremely happy with mine and my wife ended up getting one too. Both of us have made significant improvements to our health; I'm down 40lb (back to high school graduation weight!) from eating better and exercising a lot more; she's losing weight and exercising more than ever. I'm even running significantly faster than I used to.I think the biggest, most helpful factor has been the calorie tracking. Losing weight requires burning more calories than you're eating; no way around that. I think the problem is that most people, even if they track their calories, have no real good way of knowing what they're burning. I had the same problem; without knowing what I'm burning the food target is a stab in the dark. Either you're a lot more active than you think and you way underestimate your calories burned, feel like crap because you aren't eating, and give up; or your calorie target is too generous and you give up because you aren't getting results.Enter Fitbit. Wear it consistently and put your information in accurately, and it's likely going to give you a pretty good number to go by. If you know what you've burned, you know what you can eat, and Fitbit makes that simple with a "you have XXXX calories left" display. You'll still have to observe and adjust over time to learn your average error rate (I'm generally off by about 120 calories/day based on weight trends) but once you know that you can correct for it.The other nice thing with tracking is that, if you're like me and you work out and exercise so you can eat, you can reward yourself for an especially active day, or tack on a workout to make extra room for a special meal, without blindly guessing. I can't tell you how many times I've gotten to the end of the day and tacked on a brisk walk or HIIT workout just so I can go eat dessert or have a beer or two. You can have as many "cheat days" as you want, as long as you exercise enough to make up for it!Another interesting side effect is that it's made household chores like mowing the lawn or cleaning less of a pain. Mowing in particular burns calories off like a workout, so it's like getting rewarded with food for doing chores!In all, it makes losing weight (fat) simple. Now, I didn't say it was *easy*--it still takes willpower and enduring a little discomfort--but it basically takes the guesswork out. Unless you go out to eat at a non-chain restaurant; there you're on your own to put in your best guess for what you've eaten...