Like all waterproof breathables it is waterproof but not breathable. I will, however, take a jersey damp from sweat over one drenched by rain.
The cut and fit are great: close to body. The size chart on this is bang on. I have a size large; am 175lbs; 5'11" and 39" chest. Gore often sizes their waist a bit out of proportion (larger) relative to the chest on most of their jackets...maybe it's a NA vs Euro body type thing. This jacket is no different but not as pronounced as a couple of other Gore jackets i own.
The reason I cannot give what is otherwise a perfect, simple, light well built shell 5 stars is the use of neoprene. Gore seems obsessed with the stuff as so many pieces incorporate it often in the collar or cuffs, as is the case with this Oxygen.
At the ends of the arms on a rain jacket like this, by using neoprene, one now has what are effectively sponges. The neoprene serves no other purpose but to soak up water. The issue is compounded if temps are low (colder wrists) and wearing a long sleeve jersey underneath which now soaks up the water through the soaked neoprene cuffs. Also, neoprene takes a while to dry, so say you wore the jacket on your morning commute you get to throw on your waterproof jacket with already soaked cuffs for the ride home.
gore, if you're listening: stop with the neoprene on all of your stuff. It does not breath. It soaks. It frays, separates and looks like crap with use (especially with open edges like on all of your stuff).