Do yourself a favor, go with the steel. I rode an aluminum Colnago that feels like a buzz saw on your crotch. Built a steel Bianchi this year and what a difference. The roads in the Midwest suck after a long winter and the steel sucks up the bumps and road vibration like nothing else. Century rides are fun again.
Steel has the added advantage of lasting forever.
The only thing that has more longevity is titanium. Ride the steel, save the aluminum for racing. The guys are right. Just make sure whatever bike you get, that it fits you perfectly, and feels like it's part of you when you are riding it.