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Garmin Fenix 5 Review – The Honest Approach
Most reviews of the Garmin Fenix 5 start out with a quote along the lines of,
…it’s fair to say that the Fenix 5 is the best watch Garmin has ever made…
I’d prefer to say it’s their most feature-full watch ever made.
Which is not quite the same thing.
I’m debating how I undertake reviews by thinking of following the usual ‘sports watch review route’ in the future. IE not buying a device, then not testing it. Reading the manual and then copying chunks of reviews by several other people and then mostly saying positive things as a conclusion with a token irrelevant, negative point or two. Not forgetting to add a link for the reader to buy the aforesaid sports watch.
Couple that with not taking any images of the sports watch myself and I will save myself a whole lot of time and money. Actually I’d probably MAKE some money out of the referral commissions!
That strategy will, of course, require me to re-kindle a dependent relationship to Garmin where I rely on their generosity in providing a timely and free PR sample with ‘no strings attached’.
Yeah right.
Here is my original review of the Garmin Fenix 5 range which I thought was a ‘fair’ view as it included some negativity.
Garmin Fenix 5 Review including | 5x | 5s | Forerunner 935 |
I’ll stick by what I wrote then, and subsequently; which, in a nutshell, is:
- Awesome feature set and good build quality (apart from some straps)
- Optical HR is not great in anything but steady state running across all Fenix devices.
- Optical HR is particularly not great on the Fenix 5X, perhaps due to its weight
- GLONASS is poor.
- GPS accuracy is ‘meh’ ie in line with cheaper devices but, on the whole, below the accuracy of other brands of devices.
- There are show-stopper issues for some people with ANT+ connectivity issues with the Fenix 5 and Fenix 5S
And don’t forget a lot of the insightful Firstbeat metrics rely on the accuracy of the optical HR…
GLONASS Evidence:
It is what it is…

ANT+ Sensor Evidence:
They certainly do…

Although many of us kinda knew that in May or earlier, as did Ray – I assume he probably knew earlier than that. Very few other reviews (than his) mention this major issue – I haven’t seen any others in fact.
So don’t just take my word for it. Or Ray’s word for it. Try taking in the views of some Fenix customers on the Garmin forums (link to: garmin.com).
Also my thoughts on a recall and why it will NEVER happen are here:
Fenix 5 & 5s RECALL ? – Would you do that if you were Garmin right now?
HR Evidence
Many times the Fenix 5 is OK…many times it’s not OK. To be fair, many similar optical HR performances are found with other vendors. But the other vendors have cheaper products.
Question: Would you accept that level of performance from a bike power meter?
GPS Accuracy
Here is the formal GPS methodology, course and source files over several devices but broadly it’s…
Compare to other devices as I’m training. Then do a formal test over a 10 mile run with challenging GPS conditions, taking both sets of data into account.
I’m no scientist and obviously my GPS testing methodology is rubbish and scientifically flawed?
Obviously.
But then someone else with a different methodology finds essentially the same thing.

Inconvenient.
Altimetry
These lines should at least be parallel.
They’re not.
The Partial Solution?
- Buy a Garmin HRM-TRI heart rate monitor an awesome product – see! I like some Garmin products (the good ones). The HRM-TRI gives you great heart rate and lots of exciting caching scenarios
- Buy a STRYD – super accurate footpod running pace and distance whilst also giving you running power. Or another footpod.
- Once you have STRYD, all you need the Fenix 5’s GPS for is the pretty post run track of where you’ve been. The Fenix 5’s GPS is fine for that purpose.
- None of that will help with the navigation on the 5X’s rather pretty maps though.
Wait a minute…
You say, “That must be biased advice. You are getting me to spend money on STRYD (or other footpod). Surely that’s taking the argument away from accuracy and onto other things as a solution?”
Well…I suspect that Garmin will soon soften up existing Fenix customers and entice more new customers to the Fenix range with yet more new features. And I suspect that by adding new features, Garmin IS taking the argument away from fixing accuracy and onto other things. ie shifting the focus to ‘adding new features’.
Let’s say you wait for the imminent RunPow (Garmin Running Power, GRP). I bet that will soon be “proven” by many reviewers to be “better” than STRYD’s power AND IT’S FREE. So c’mon people RunPow only works on high-end Garmin devices, “it’s time to upgrade your old hardware” (links below 😉 ) Kerching….errr…not free.
My Point: Well yes, it’s free for existing owners. But it’s also based on the Fenix 5’s GPS and altimeter. I’ve covered those two points above? You will want to display accurate 3-second power perhaps…like on your bike? Based on accurate 3 second GPS pace. ie instant pace. Remember, you can’t get accurate instant pace from ANY GPS device…at least none that I know of.
Do you use a Powerpod? [I do, but not as a main device BTW] So if you can take PowerPod’s stated +/-3% accuracy for your bike power then maybe all will be good with the accuracy of RunPow. I don’t know the accuracy of RunPow yet but I would be happy with 3 accuracy that’s equivalent to +/-150m over 5k
As an aside: Admittedly STRYD is quite expensive, RunScribe might turn out to be accurate too. Let’s see.
Must Read: STRYD Review
The Rumours
There are rumours of a Fenix 5 plus version to be released early next year ie one with the ANT+ issue fixed and maybe other features too. I’ve no idea if those rumours are true. However, I do tend to believe the sources of that information. I don’t know if Garmin need to make that change as their share price is going in the right direction despite some recent issues in certain fitness-related sectors.
Inconvenient Truth
The Inconvenient Truth is probably that, in many cases, people want to read information and advice in a review that supports a decision they’ve almost made in their minds. Hence the overly positive reviews might work better than the ‘fair’ reviews. Maybe? Just a thought.
Maybe the positive reviews tip people over the purchasing precipice?
I was a little surprised. But, on reflection, I suppose it makes sense.
Sour Grapes
I started off my original Garmin Fenix 5 review with this line
However this review will dwell a little on the more negative aspects of the Fenix 5/935. You can read lots of positive reviews all over the internet. However out of respect for you wanting to do your research properly I’ll try, at times, to present a counter argument to the prevailing wisdom.
I was intrigued to see if such an approach would generate more affiliate sales for me
It didn’t 🙂
I don’t make that many affiliate sales anyway…this is an enjoyable hobby not a job.
So what are your thoughts on what buyers should do as well as on what reviewers should do? My tentative conclusion is that we all seem to want to live in a rose-tinted tech world. Which is a bit of an indictment on the human condition…or maybe the opposite. Glass half full or half empty?
The Garmin 935? Even though it is a Fenix 5 in all but name, it is probably one of your best bets for a new sports watch for a variety of tri-related reasons. I returned mine a few weeks back (another story) BUT I will re-buy one in the very near future (Edit: just bought one today 22 nov). And the GPS is better on the 935 than the older 920XT in any case. Go on…get one. You know you want to 😉