I guess I'll be the only one to answer your question. . .

I bought a Metropolis 6 years ago, and gave it away when I got my mini-metro two years ago. I think I paid something like $130, so you're getting a good deal. It's definitely quite large, I can fit my 13" MBP, several textbooks/notebooks, calculator, lock, and some drinks in their with no problem (I've been known to fill it with ice and beer on occasion). For day-to-day, non-messengering use, the mini-metro is definitely the most reasonably sized, and of course it's incredibly high quality. My metropolis is still going strong for my friend. My only precaution would be that you shouldn't buy a bag like this unless you'll be on the bike with it a lot. They're not as comfortable when you're walking with heavy stuff inside. I have a backpack for when I'm not going to be biking and have a ton of **** to carry.