There is no way for me to stay dry on the bike if I'm out for more than a few minutes in real rain. If it keeps water out, it doesn't breath well enough.

I own obscenely expensive, heavy-duty, Goretex foul weather gear for ocean racing and I'm always wet when it gets snotty, from the outside, the inside, or both. I haven't invested in good rain kit for the bike, but have given up on the entire concept of dry and just try for warm.