645 vs Fenix 6 comparison

I don't think it's a fair comparison. I am also a former 645 owner and just got a Fenix 6S Pro. The Fenix 6 series is better in just about every respect, as you would expect for a watch costing twice the price and 2 years newer.

I won't go into detail, but the main advantages over 645 that stand out for me after just a day of owning the Fenix 6S Pro are:

- Better build quality - Fenix is a solid watch. The plastic case on the 645 is starting to feel quite smooth to the touch from general wear and tear, whereas the case of the Fenix 6 has a kind of textured feel to it, which I think will stay looking new for longer. Buttons have a reassuring click and good tactile feel, whereas buttons on my 645 have gone soft;

- Looks - I went for the all black edition, the Fenix 6S Pro is a smart looking timepiece, and the stainless steel back gives it a quality feel which you don't get with the Forerunners;

- GPS performance is significantly better - tracks have so far been very good, and superior to the 645 and 935;

- Altimeter - the 645 altimeter was very unreliable, whereas the one in the Fenix 6 is very accurate and will auto-calibrate from built-in topo maps;

- One point that is quite important on a daily basis and often overlooked: the overall reactivity of the watch in the menu and the improvement of the processor;

- Native navigation app (you can navigate without having to start an activity);

- Native altimeter and barometer apps;

- Pre-loaded maps! They are better than I thought they would be (in the UK);

- Ability to see heart rate and altitude on the watch face without needing to use third party Connect IQ watch faces;

- The way the widgets are displayed is way better.

Things I don't like:

- Comfort - I'd be lying if I said the Fenix 6S Pro was as comfortable as the 645, as it's taller (lug-to-lug) and 20 grams heavier (although the lugs have reduced in length since the Fenix 5S);

- Fit - the Fenix 6 won't stay flat on my wrist when I am running and covered in sweat, probably due to increased weight and taller lug-to-lug design, and this makes it harder to read the data fields during a run as the watch is always at an angle.

- Strap - I don't know why Garmin made the strap so short on the Fenix 6S. It should be the same length as the one on the 645. It fits me but it's on the short side so it makes it more cumbersome to put it on. 

Hope that helps.

Agree with your points and it is not a fair comparison, the F6 is definitely a higher quality device which you would expect at the different price points. I posted as I know a number of 645 owners are considering upgrading and it helps to show the difference in size/looks. 

Thank you for that. Could you post a couple of photos of the 645 and 6s side-by-side (here or in a new post)?

It is sooo frustrating that they make the bands on these watches so freaking small

I lift and my wrists are quite large. I've had to purchase aftermarket straps, which is ridiculous after you've already paid $300+

I will also add that having tried a 5k run this morning with the Fenix 6, taking the same route as I did last week using the 645M, the GPS tracking of the Fenix 6 is clearly not as accurate as the 645.

This was a timed 5k Park Run on both occasions and taking the same course. It is possible there is some user error on the start point, I'll be able to validate this when I get the official time back. Other than the start/finish section the remainder of the route is a single path about 10 foot wide, which goes under the highway. You can see that the Fenix 6 struggles to keep the track as tight.

645M

Fenix 6

Unfortunately I am returning the Fenix 6 due to a screen defect, however I've also encountered an intermittent wrist OHR (as have a fair few others), plus the lack of SDK and apps (even Garmin ones such as Running Power) is disappointing. I expect the firmware will improve in the next couple of months and the apps will become available, but I depend on my watch on a daily basis to be able to wait, so I'll be getting a refund.

TheSalamander

Funny, I was just looking at that course map yesterday while trying to find a local 5K. :) Assuming everything worked as it should, do you like the Fenix 6 better than the 645M?

The Fenix 6 has a lot of potential, but for me it is not ready to use as a replacement for the 645M, mostly due to firmware issues and lack of apps that I use.

Assuming you don't mind the larger size/weight (and I think most people would get used to it) then it is a definite step up from the 645M, in part due to the updated software which would presumably come to the 655 next year.

At present I am going to wait a couple of months and then decide if I go back to a Fenix 6, or wait for the 655M. Assuming that PacePro, Body Battery etc come to the 655 then the only real benefit that I would get from the Fenix 6 would be the extra battery life since I don't do triathlons and don't really need the inbuilt maps. Other than that it comes to aesthetics, and without trying to stereo type I could see a lot of guys preferring the style of the Fenix 6 over the Forerunner 645/655.

TheSalamander

It's funny that because I have been testing the 645 and Fenix 6S together on the same run both using GPS + Galileo and the Fenix 6S comes out as the winner with better tracks. The 645 also suffers from really inaccurate lap pace at the start of a run and sometimes for the first 20 seconds of each lap. Often it is about 45 seconds per mile out, whereas the Fenix 6S is much more stable. But at the end of each lap, the two watches are almost identical on pace. I have found the Fenix 6S reads a slightly shorter distance on the same route, by around 0.05 miles over 4 miles.

I think I need to do a certified race course to know which one is true but the tracks do seem tidier on the Fenix 6S.

See for yourself:

645: https://connect.garmin.com/modern/activity/4032688175

Fenix 6S: https://connect.garmin.com/modern/activity/4032687151

645: https://connect.garmin.com/modern/activity/4037808666

Fenix 6S: https://connect.garmin.com/modern/activity/4037814846

One thing that is definitely better on the Fenix 6 is the altimeter. The altimeter on the 645 sucks. Altitude compared to ordinance datum was always incorrect. It required constant calibration for the data to be meaningful. On the Fenix 6 it just works all of the time and it self-calibrates with the built in topo maps. You can also use it without being in an activity, and it even has a live data field on watch face, which is cool.

Hi guys, I thought that rd pod only doesn’t turn on for me on f6. Does anyone know a solution? or have to wait for new updates.