Utility
Neither the Dodge Durango nor the Aspen has a marked advantage in terms of seating capacity.
The Dodge Durango is a better choice than the Chrysler Aspen when it comes to transporting cargo, especially if you often need to carry a lot of loot or large dogs.
The Chrysler Aspen outpulls the Dodge Durango by a large margin.
Dimensions
The Dodge Durango and the Chrysler Aspen compete for the same parking spaces.
Cost
With respect to MSRP, the Chrysler Aspen costs approximately as much as the Dodge Durango (though the Dodge Durango is a bit cheaper).
Handling
With their comparable turning circles, the Aspen and the Durango most definitely handle almost the same into and out of tight spots.
Warranty
The Chrysler and the Dodge Durango have the same basic after-sale protection.