Our competitive swimmer daughter begged for Phlex Swim for a year after researching the device and the app online. Here are her observations after two weeks of usage in an indoor 25 yard pool:
Device was easy to position on the goggles and the goggles do not leak. Strong recommendation to wear goggles under the cap or to double cap.
Device is responsive and measures a lot of metrics and she is still amazed at how it "knows" when you are splashing around at the wall vs actually swimming because it records swim intervals very precisely and knows workouts targeting 50's, 75's and 100's. The splits are very accurate and keep her focused.
She likes that the heart rate can get measured by 1 min. so she can tell exactly in what zone she was swimming vs "average" rate. It helps her stick with effort targets.
She is still exploring all the metrics she can analyze but the feature to give her coach visibility into practice metrics captured by Phlex Swim app has great potential and will help them analyze swims together.
So far the device holds the charge well. She does put it on the charger after each practice though ("just in case"). We have not tested it in open water yet due to cold season but the intent is to use it primarily for OW practice once the weather warms up (the swimmer in question is a triathlete).

Great tracker! Accurate. I had a little trouble avoiding goggle leaks but moved the tracker back on my straps some which solved the problem. Great data on the iOS app.

My pool and many others in my area have been closed due to the pandemic and then when my pool opened again the pump was hit by lightning and has been out of service for the last 3 weeks so I have not been able to use it yet.

Love my Phlex

!! The idea of just getting ur heart and seeing how ur heart beat in ur session is out out of this earth !! I love it

I like my Phlex

My order showed up at the door a couple of days after ordering. Polish swimmers are falling in love with the EDGE!

I used to have several fitness trackers for swimming. EDGE is the first tracker for me that is so easy to use and so functional. The ability to simply turn on the tracker with one button at the beginning of a workout and turn it off when you get out of the water, being fully confident that all the training series and exercises will be correctly recognized - this is priceless. Very accurate HR measurement-repeatedly compared with manual measurement. Very good basic Analytics, but I am sure that in the future it will become even richer. The only thing I really miss is the metronome function. It would be very useful for long-distance training - to be able to set a vibration alert for a given time interval for example, every 40 seconds (assuming 40 sec per 50m pace) so that you can keep this pace for a long time at each pool and control your speed. Similarly, it would be very good to be able to set a short vibration alert for each stroke (setting the stroke frequency). These functions are very popular in my training process. Finally, it would be useful to be able to view analytics not only in the 100m section, but also in the 50m section (for example, when the first 50m do an exercise, and the second 50m swim a powerful long-stroke freestyle with a focus on the exercise just done and then pause for short rest - it is interesting to see data for each 50m separately, and not the average amount for all 100m).

Great product! Love to swim with it. Great customer service.

Excellent training tool. Excellent feedback. Good accuracy comparing timer in the device with my times on the pace clock. Measured the intervals accurately as well. Streamlined, so it doesn’t move out of position or cause water to get into your goggles on a push-off.

I wish a platform like this existed when I was swimming competitively. Since retiring I have used my EDGE for all my swimming workouts. Would recommend for all levels!

The Edge and Phlex are the swim tracking solution I have been dreaming about since I tried the first swim apps years ago; swim my workout, and the app figures it out and logs what I did.

We entered the next level of workouts tracking. An INCREDIBLE piece of technology, makes me want to ENGAGE in my training much much more than before. Gamification of the workouts but also an incredible tool for tracking. Acts as an assistant, and makes it much easier to train efficiently. Highly RECOMMEND for all caches and swimmers seeking more awareness. We've got two so far but will likely purchase 10 more for the entire group sometime soon.

It really individualizes your workouts for your athletes, helps them become students of the sport and helps you analyze their training.

One of the greatest things about this product is that it's not a distraction, it's super easy to put on and it's not taking away any time from practice. Coaches love that, swimmers love that. Yet once we’re done we actually have something to physically look and review. I think that's a huge training tool for us to have.