Just bought the GWM 5610U-1C. It was a tough decision choosing between the DW5600 and this, ended up choosing this because the atomic time keeping is cool.
However, I’m a tad annoyed that the time doesn’t perfectly match with time.gov and time.is since the atomic sync doesn’t account for time propagation, so there’s like a fraction of a second delay that’s noticeable. Other than that, the watch is fantastic and has most features I would want. (I wish it had barometer and altimeter stuff, maybe even compass, and dive rated so I can press buttons underwater)
The watch would be radio controlled so the delay wouldn’t be determined by the network infrastructure but by the interference in the air. The watch’s stopwatch can do split second 1/100 so surely it is precise enough. I’m leaning towards this being an issue of interference.