I understand that the distance accuracy used to affect running more than other activities. I don’t run, but I noticed that my R2 was always a bit short on distance when cycling. Not much, but noticable. Around 300 m on a 50 km ride. It was somewhat frustrating when my ride was just 50.2 km and it was reported as 49.9 (as if I did not reach my target ).
The latest update improved the accuracy. It is still a wee bit short, but it seems that it might be missing <100 m (70-80) (still on a 50 km loop).
In all cases, I compare the Strava distance, a Garmin (Edge Explore 2), and R2. The difference might be also due to different ways each tool treats stops and pauses (I.e., how much distance you have to move or what speed you need to reach before they assume that you are moving again).