I had high hopes for the 935 model after reading the reviews, but I am incredibly disappointed. GPS tracking is way off, it has a difficult ti.e following roads, it doesn't track trails very well, and you can forget about trying to track your open water swim. Maybe the one I got is a dud, or maybe the 935 is garbage. Either way, it's going back.

As someone who has owned multiple Garmin fitness watches and products, I was excited for the 935 when it came out last year in 2017. I got this watch as an upgrade to my 920 as it had new performance metrics using the HR wrist sensor I was interested in. I swim, bike, and run so it got to see fairly good use in the year since I purchased it. What would have been a 5-star review has become a 1 star do to some glaring issues on a $500 watch (at the time).Detection of the swimming stroke I was performing was in the 60-75% accurate range. I could never do sets of multiple types of strokes with it being 100% accurate. I did 3x sets of 200 I.M.s this week during a session and only once did it detect my butterfly stroke and only for 1 pool length, not even on the return (watch said it was freestyle). If I did the strokes separately, it did a better job of detection, but I still had issues with missing lap counts (it doesn't like my breaststroke or if come up to short on my backstroke flip turn).The next issue has been the back plastic coating on top of the HR sensors. As you can see from my photo, it has started flaking off. Unacceptable for a 500$ watch and only a year of use. I can't trust my HR readings to be accurate and thus can't trust that the performance metrics I was interested in are accurate.The last issue is that the temperature sensor and barometer sensor no longer can calibrate correctly. I have maintained proper care of the watch as I use it in the pool regularly but again a 500$ watch shouldn't have this issue a year into its use.To make matters worse, I'm 4 months beyond the 1 year warranty period set by Garmin so I can't resolve these issues. You can search the internet for these problems and readily come across other purchasers who have experienced these issues so I'm not the only one. If you follow DC Rainmaker, he gives a really good review of this watch but these issues are a showstopper for me, especially the poor build quality in a 500$ watch. If it weren't for these issues, it would easily get a 5 star rating. There are so many metrics to track and Garmin put a lot of effort in the app so you can use that data. Until these issues get fixed, I can't overlook that and recommend it.

Does not connect to Wi Fi. Garmin's answer is they can't test it with every router. (?). So forget about auto upload. Garmin Connect is terrible. Layout is lousy. Nothing intuitive or logical. But the question is, why should you need? Shouldn't Garmin Connect Mobile do everything? Unfortunately it doesn't. You need both if you want all of the features. And of course you still need a third program, Garmin Express,to get any updates or to set up your wifi. WHY? Maybe it wouldn't be so bad if the web and mobile programs were better. And lastly, the watch sometimes freezes when it is disconnected, after doing the proper eject of course, from your computer, which you have to do in order to use Garmin Express. Garmin Connect comes with Training Plans, all of which are barely explained. So which one should you use? Garmin Connect also has a feature to create custom workouts. Very tedious and not that powerful at all. The Garmin hardware seems great, but consistent with my experience using their GPS devices, they just don't get the software right.Reduced to 1 STAR.The unit does not operate as described. It "freezes" after using Garmin Express. It does does not pair with any wifi networks. It gives random alarms. It does not perform as programmed from Connect. It continually re-pairs with the RD POD in use and gives a message POD is now connected, which covers the top of the screen. Lots of other software bugs too numerous to mention. GPS coverage is terrible under trees.Update: I've been using the replacement for 3 weeks now. Its looked promising as they seemed to have fixed the wi-fi connection problem. But I give up. This thing just does not work. The heart is still giving readings all over the place. So much that I have to question whether any of the exotic and sophisticated health parameters that are based on heart rate can possibly be useful, like HRC, lactate threshhold, recovery, etc.). Pace data is still poor. Even with all the smoothing that the internal accelerometer is supposed to help with, and using foot pods that are supposed to help, its still erratic. Operationally needing needing 2 versions of Garmin Connect, web and phone, and Garmin Express is I think ridiculous. That last straw was when Garmin Express failed to recognize the 935. (Yes, I reloaded Garmin Express, and updated, and blah blah blah.) , and still wasn't recognizing it this morning. Overall there is nothing easy about using this watch. Workouts are not easy to create. They can't do even simple plans that my Nike iPod could do10y ears ago. Connect IQ is a real pain to search through. The apps on Connect IQ are not in any way certified by Garmin so they give you problems (but Garmin does give you a warning about this). I wanted a watch so that I wouldn't need to run with my phone. Unfortunately you need the phone for music and some of the apps and widgets. So what's the point? My iPhone gives heart rate data and pace. And when I'm wearing the phone on my upper arm,I don't need a message on my wrist that its ringing. There's lots more that I could mention, but i'm done with typing and this watch. Garmin needs anew project software engineer and needs to fire at least one vice president.