Aluminum is more durable than plastic and has more strength. Aluminum is very strong and resistant to impacts. Impacts on a aluminum dog crate is absorbed within the distortion and not transferred to the content. With plastic dog crates, when an impact occurs the case will often flex or deform and transfer the majority of the impact energy directly to the contents. The plastic dog crate will crack and possibly allow your pet to escape on Impact.
Aluminum is hygienic and easy to clean and has no odor, plastic crates can collect unsavory odors over time. This can make it more difficult to keep a plastic crate clean and hygienic.
Aluminum dissipates heat much quicker than plastic.
Aluminum is completely recyclable, unlike cases made of plastic
Aluminum is impervious to the degrading effects of UV Rays. Most plastic dog crates unless mixed with special UV blocking materials will discolor and brittle with age.