I've got a '91 520 that I picked up used for $100 last summer. I'm not as familiar with the specs of current 520s, but my older one is not an ideal loaded/expedition touring bike. Like you said, a bit heavy and not long chain stays. I personally would put it in a light/sport touringish niche. However it has become my daily and light-load touring bikes -- I've been super happy with it, especially after updating it with a few of my favorite components (Technomic stem, Noodle bars, Power Grips, etc, etc).