That's an interesting question.
Aluminium conducts heat well, which means it should heat up quickly and uniformly, but also will mean it looses heat quickly also. It's not clear to me whether that would ever be an issue in dutch oven cooking.
Cooking acidic foods in aluminium pots is a no-no. That's why aluminium pots are usually either a sandwhich construction where the interior is some other material, or in some cases I think there are pots with some sort of coating on the interior. Don't know whether the DO you saw has some sort of coating, but if not that would be a limitation on what types of foods can be cooked in this DO.
Don't know the answer to this question, but I wonder if aluminium would accept and hold seasoning the way cast iron does.
For vehicle based travel the weight of a dutch oven or two is a small part of the overall weight of vehicle & gear, so I think I'd stay with the tried and true cast iron for my dutch ovens.