I have given up on waterproofs....they keep you dry from the outside but you sweat so much inside that they do not stop you getting wet. The lack of ventilation makes it cold and wet which is worse than not having waterproofs on.
My preferred method is to wear several layers (baselayer, bibtights, long-sleeved jersey and light gilet). When it rains I will get wet, but the layering acts like a wetsuit and I keep warm while moving. I just make sure that I have a full set of clothes too change into at my destination.
It is physically impossible to purchase a waterproof that does not make you wet inside, however breathable and waterproof the manufacturer claims it to be.
If you are ambling along at 10 mph, perhaps you won't sweat, but any light effort will produce moisture and make you wet, probably more than without a waterproof!
For the record, I have a Montane Featherlight H2O and it is great at sealing in the sweat! By the time I get home, the wind has usually blown my outer layers dry and I take off the Montane to find soaking wet underlayers.