Bridgestones were good--most from that era were designed by Grant Petersen, who went on to found Rivendell and build some great rides.
I don't know much about the 300, but my wife has a 500 (couple of steps up) she's owned for 15 years or so. It's been a really good bike, and it's intelligently designed, like everything Grant does. If it's in decent shape and the price is right, it should be fine for commuting. You don't want an expensive bike for that anyway--they get stolen a lot.