This is my daily driver, a 1992 Trek 820 in electric blue with black spatter. I got it for free from my brother about a year ago, and have since put ~4K miles on it. I have another 820, and I love these bikes. They make great city bikes. They're dirt cheap, geared well for the hills in my area, and they just work. It's nice to have something in your life that you don't ever have to even think about. I've made some upgrades for my use, including the racks, basket (I have a second I attach to the front rack for Costco runs), fenders, street tires, and high rise handlebars.
Aluminum is hard on the ass and Carbon makes those cracking noises that cost 5K each time you hear one. Steel is the metal to beat for service life.