Got you. I've had issues with waterproof jackets before that are totally waterproof but not at all breathable so you end up with a load of condensation on the inside of the jacket, negating the benefits of being waterproof. Any idea if this is likely to be the case with the commuter jacket?
Sadly it's exactly what happens with this jacket. It's OK for walking (or if you're never hot like @HoKe), but if you do any activity you will be wet from inside. I think even my Core Rain Jacket is more breathable than the Commuter one.
To echo what others have said, while it may keep the rain off you, you're still gonna end up wet if you're going at any more than a walking pace. Probably the only time I've ever experienced sweaty arms.
I wouldn't say it's breathable at all, but it's 100% waterproof and durable.