I feel that I should start out by saying that I love my Gear Fit and I use it every day. However, I don't believe that the product works nearly as well as I expected it to, and many of the stats it is meant to monitor are inaccurate.
The step counter is one of the primary features I intended to use when I purchased the product. Unfortunately, it seldom comes within 1,000 steps of what I actually count myself when I have tried it. Oftentimes the Gear Fit will miss several steps at a time, or record the slightest movement of my wrist as a step. It's very finicky.
I also find that the wake-up gesture only works around 25% of the time, which can be troublesome if you're trying to use it like you would any other watch.
The heart rate monitor is also not terribly accurate, but can give an okay estimate within 15 bpm. It does not work at all for me when using the Google Fit app to record my heart rate.
I do, however, really like being able to answer and reject calls from my wrist when my phone is out of reach, and I have used the "Find my phone" option numerous times. (Some of which were unintentional, of course). I would also mention that being able to read and respond to text messages is a huge plus, but only if you're using the stock messaging app on your phone and have taken the time to add preset messages within the Samsung Gear app.
The range of the device is better than expected. I can connect the Gear Fit to my phone from two rooms away, and I have never had an issue with it disconnecting when my phone is nearby, such as in my pocket or purse.
The display is very crisp and bright, with five brightness settings to choose from. Even on the highest brightness setting I can go about three days without having to charge the device, which is impressive.
The screen of the Gear Fit itself has proved to be durable, but the metallic edges have scraped away quite easily. (I have included two images of this). As for water-resistance, I'm quite scared to properly test this, but I have submerged my Gear Fit in the bath on accident twice now without any issues, so I'm not worried about it being damaged by rain when I'm out and about.
The Gear Fit-specific marketplace in the Play store is very disappointing to me. I expected to have the same kinds of options as the Android Wear community, but the Gear Fit developer crowd is not nearly as active.
Overall, I would not recommend this product. I think that there are definitely areas to improve upon and I expect a much higher quality from Samsung products, but I have not owned any other smart watches and I cannot say whether there are better options out there. If you're purely interested in this product because you'd like to keep track of your workout goals, I would recommend that you research all other options first.