I ride a roadie to work now. I started commuting on a rigid mtb with slicks and a delta seatpost bag for a few months, but the roadie bug bit me. I ride a yellow/blue Lemond Zurich now, the steel frame is good for commuting. I usually end up driving one day a week and thats when I restock my clothes and food supply at work. If I do need to bring something to work on the roadie I just wear a small backpack.

Are you going to have alot of stuff to bring or you just dont think you will like a roadie? Either way I would shop on ebay or craigslist for a used bike. You can usually get something better that will last longer and have better components for the same price. If you must get something new you can also look at some cyclocross bikes in the same price range as the Portland, the Redline Conquest disc and the Lemond Poprad disc are nice option if you like the discs on the Portland.