Ideal for a mix of carpeted, flat indoor, and smooth outdoor surfaces.
Ideal for outdoor use, walking tracks, and other terrain.
Generally speaking, everybody should go with a carbon fiber frame because it is the absolute easiest to lift in and out of a car.
If the weight is critical, go with carbon fiber
Depending on your lifestyle the extra weight of aluminum might not be an issue. For example, if you don't often drive alone.
If weight is not critical, aluminum is the more economical choice.