This jacket is comfortable and waterproof.  I ran it under the faucet for several seconds just to be sure.  It's very light, and I tend to keep it rolled up in my laptop bag.  The inside does have a rubbery texture, as some reviewers have commented, but that doesn't bother me.  There's a velcro strap designed to hold the hood if you want roll it up and go 'hoodless'.
The size I ordered is also right.  It's made to fit comfortably over heavier clothing such as sweaters.