2mm by itself isn't any real indication. Even if both gauges were calibrated 2mm is still possible and acceptable depending on rain rate compared to the different gauges. As for factory calibration don't read too much in that, calibration is something a little different relative to the imperial or metric counter weights that can be fitted. The other thing is how do you know which is actually off (if any), all things being equal I would take the VP2 over the Vue
Well just looking at surrounding stations, they seem to be closer to my old Vue. I know I shouldn’t go by nearby stations, but they are pretty close within 3km.
I would stress that the VP2 is roughly 2.5 metres off the ground, but it’s the best I can do with my garden due to buildings. But the Vue is literally the same height and right beside the VP2.
Today for example I had a light shower.
My old Vue recorded 0.2mm
The new VP2 recording 0.0mm
When I took off the rain cone of the VP2 and I found that the tipping spoon was nearly full of water but obviously not enough to tip the spoon.