Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Coros - PACE 3 | Polar - Grit X2 Pro |
|---|---|---|
| Smartwatch mode | 17 days | 10 days |
| GPS mode | 38 h | 43 h |
| ECG | false | true |
Between the PACE 3 and Grit X2 Pro, the PACE 3 comes out ahead in smartwatch mode, while the Grit X2 Pro wins on gps mode / ecg. Overall, the PACE 3 scores 71.4 and the Grit X2 Pro scores 68.3 on our Mars Score.
Which should you buy?
The PACE 3 edges ahead on the Mars Score (71.4 vs 68.3), but the 3.1-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the PACE 3 if you care most about smartwatch mode. The biggest gaps in its favor are smartwatch mode. The single most decisive one: Smartwatch mode — 70.00% more. 17 days vs 10 days.
Pick the Grit X2 Pro if you care most about gps mode / ecg. Its strongest claims are gps mode, ecg. The single most decisive one: GPS mode — 13.16% more. 43 h vs 38 h.
Both ship with comparable multi-band gps, solar charging, so those specs do not separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: Coros - PACE 3 or Polar - Grit X2 Pro?
Coros - PACE 3 leads the current Mars Score by 3.1 points.The more useful decision is the trade-off behind that result: compare smartwatch mode, gps mode against the way you will actually use the product.
Choose Coros - PACE 3 if…
Coros - PACE 3 has the measurable edge on battery smartwatch days.
Choose Polar - Grit X2 Pro if…
Polar - Grit X2 Pro has the measurable edge on battery gps hours, has ecg.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Coros - PACE 3 wins
- ▲Smartwatch mode — 70.00% more. 17 days vs 10 days.
Why Polar - Grit X2 Pro wins
- ▲GPS mode — 13.16% more. 43 h vs 38 h.
- ▲Has ECG.
Spec comparison
GPS & Sensors
| Spec | Coros - PACE 3 | Polar - Grit X2 Pro |
|---|---|---|
| Multi-band GPS | true | true |
| Barometric altimeter | true | true |
| Heart rate | true | true |
| ECG | false | truelead |
| Pulse Ox | true | true |
Battery
| Spec | Coros - PACE 3 | Polar - Grit X2 Pro |
|---|---|---|
| Smartwatch mode | 17 dayslead | 10 days |
| GPS mode | 38 h | 43 hlead |
| Solar charging | false | false |
Design
| Spec | Coros - PACE 3 | Polar - Grit X2 Pro |
|---|---|---|
| Case size | 42 mm | 47.5 mmlead |
| Weight | 39 glead | 79 g |
| Water resistanceⓘ | 5 ATM | 10 ATMlead |