I have the X1C. Little thing I noticed about the matte IPS screen (which I selected for outdoor usage much like you said) is that the screen goes black when I wear my sunglasses with a polarized lens, so if your sunglasses are polarized perhaps consider buying some non-polarized ones :-)
They would need to be the same... and if we can't get people to standardize on internet protocols, good luck with something that actually affects whether the product works well or not!