I was looking at the Zephyr, and it appears to be 'resistant' too, not waterproof. Performance has a $9.00 plastic jacket/cape-type thingy that looks waterproof, but then it has mesh inserts in the sleeves.

Skibum, let's compare notes after our rides - we were going to do the Bike Tour if we didn't get into Ride the Rockies, but a) we got in, and b) we have a hiking trip to Yellowstone planned that would overlap (yes, I'm riding in Colorado for a week, coming home and working for 4 days, then heading out for two weeks of hiking in Yellowstone - I can't believe how lucky I am!)

From what I know (a few vacations in Colorado, but usually later in the summer) afternoon thunderstorms come up from nowhere, and can last for hours. Or, just weather can move in for days. We had about four nights of camping out that were rained out in early July last year. My feeling is that if I'm going to carry something, I want to make sure it will do the job - I don't have room for gear that isn't doing its job. I'm trying to get away with a large seatpost bag for all my daily gear, so space is VERY limited.