Generally speaking....generally speaking.....

1. Aluminum bikes tend to transmit more vibration to the rider. You can call it "road feel" or "roughness" or whatever. But what matters is whether you enjoy, accept, or despise that feel.
2. A big benefit of aluminum is that it tends to be cheaper than comparably equipped carbon and titanium frames, especially if you race.
3. The downside of aluminum bikes is that when they are good they are good, but when they are bad they are horrible.