There is, understandably given forums and human nature, quite a lot of critisism here about the Fenxi 5, so I thought I would redress the balance.
Having owned my F5 for a month now, have to say I just love it. Yes it was expensive, but the depth of the feature set and the sophistication Garmin have crammed into such a small package makes it worth it. It looks great for every-day wear, the battery life is amazing, it's very customisable and it's a very good all-day smart watch. But, setting it apart from most other watches, it is an even better sports / activity watch. Running and cycling, I've had no problems with sensors dropping out, or bluetooth connectivity. The GPS tracking is just as good as my Edge1000 and the running analysis and stats are far beyond what I had on my Polar.
If you are thinking of getting one, all I can say is, it is by far, the best watch I have ever owned. And that includes previous running watches and my Breitling, which is now gathering dust in a draw!