Garmin fenix 5X Plus issues: it's that acceptable?

Just a quick comment: Even a cheap phone has a huge GPS antenna, more processing power and bigger battery compared to a watch, so no surprise a phone is more accurate.

First, thanks for reply.

I could also agree with you, but, as you can see, this is not just about accuracy, this is about the fact that my fenix created from nowhere part of the track. See picture 2, I never made that crazy spaghetti plate in the middle, see picture 3, I never went in that south out of the track part (that is a overhang, just to know). Datas were subsequently fake: kms, calories, altitude difference.. Then, I ask you, sportwatches like fenix are supposed to be made exactly for that, be a reliable support on navigation. We're not talking exactly about toys. If they can't navigate you on the right path in the middle of nowhere, what is their sense? If I just needed a watch to read notifications, I certainly wouldn't have wasted so much money on a unreliable "multisport messiah, at the pinnacle of exploration and athleticism". Luckily yesterday we went on a well recognizable path, but if I was following an off-track route? I can accept a dozen meters lack of precision, but what I saw yesterday it's honestly too much for a watch supposed to have much different specs.

I totally understand and share your sentiments. I am a lot like you, accurate and logical thinking. You won't find much support here, it's very tribal and people accept a lot of medium quality for a long time. And unfortunately, Garmin software is and always has been quite buggy. At the end of the day, as someone else said, even a simple phone can do much more than the best (Garmin) watch, apart from altimeter, heartrate and battery life. But even battery is no problem anymore with all those battery packs around. Either you like the watch, because it's 'cool', or it's not yours. If you need an altimeter, I suggest you get a designated navigation device (I have an old Etrex, great, loads of GPX-courses, waypoints and Open Source Maps on there) or get an additional altimeter and heart rate monitor with bluetooth for your phone.

Thanks you too for your reply! Well, I chose a sportwatch for my outdoor adventures, basically for 2 reasons: the (a this point, just supposed) better accuracy of a much more reliable GPS signal, and practicality that in some conditions may results decisive or at least very comfortable. In fact, on my activity I always use poles: a cartographic sportwatch lets you to check instantly if you're on route or not, just turning your wrist, while using any other kind of GPS device, I should stop, put aside the poles , open the pocket, get the device, check the route, than put back the device on pocket, get back the poles and finally start walking again. Most of the time that's just a bother, sometimes it's rather even impossible to do. For example, last sunday, at a certain point we had to going on our climbing against really strong gusts of wind, so much so that we had to walk bent over. You can understand that in situations like that you just can't check the route on a phone, while a sportwatch can be unbelievable helpful. This is not a matter of fashion, this is a matter of make your life a bit easier.

Have you tried improving the location accuracy by choosing GPS+GLONASS or GPS+GALILEO (depending on where you live)? But in the end, I'm afraid that you'll have to accept that miniaturization involves compromises (accuracy vs. weight, accuracy vs. power consumption, accuracy vs. size). What you are describing doesn't sound like a software problem but a gps reception problem in challenging situations (as you yourself mention).

Maybe you'll find this a silly idea or tried it already, but just in case: for hiking with poles, I strapped a GPS watch (Epix at that time) such that I didn't have to turn my wrist. It made better tracks than the Fenix 3 that was worn on the wrist as normal (at the same time), maybe wearing the watch differently such that it always faced upwards made signal reception better.

Some other things you can try, it takes some experimenting to find what works best for you in these conditions: settings like GPS only, GPS+Glonass, or GPS+Galileo, and as for the tracks: data recording 'smart' (works for me, on certain terrain, to smooth out squiggles) or 'every second' (works for most). Don't use UltraTrack. 

BTW smartphones can make use of more data to determine location, so if there is mobile coverage, they can do better than a GPS-only device. Mountains, tall buildings, high moisture content in the air, dense foliage etc are challenges for any GPS.

You might put that one down to using gps in a difficult area - there accuracy will depend to a great degree on where the satellites are at that time and whether the view is obscured and possibly multipath signals.   You could try the same route tomorrow and it may track pretty well.  I can't really fault the accuracy of my 5 plus while running / cycling and its as good if not slightly better than previous watched I've had.  My Oregon 700 is slightly better when hiking but its a much bigger unit so not really comparable.  The 5 plus on my wrist is actually more accurate than my Edge 520 when mountain biking in heavily wooded areas.  A phone is not a fair comparison - the antennas are huge compared to what is inside a watch and they also have "assisted" gps.  You shouldn't make a judgement based on one test - keep trying and see how you go.  No gps device is perfect partly because GPS is not 100% accurate in the first place.  I think officially the US government pledge that the error is less than 7.8m with 95% probability.  Usually its better that that.

It is a Fenix, so don't expect a good track against walls. I compared it with older watches. They were much more accurate. The Fenix is often 40-50 metres awawy from real position in not horizon free situations. Haven't found a solution for me :(

Could you name the older watches that are better?

It seems to be a problem of the Fenix series. Thus, the Forerunner models should be all right. I compared it with older watches from competitors. Old activities with friends having an older Garmin Forerunner model results in similar results. Comparing it with my Fenix has a deviation of usually about 6.5% in distance and a much more changing pace :(