It looks to me like the metal crates would be hard to clean (say if you're out-of-State and the dog has been in a swamp). I have Ruff Tuff's and am satisfied (wipe them out or take them out and hose them). I've gone thru a number of cheaper plastic crates.
I did drill extra holes in the Ruff Tuff's and have fans on the doors. I ordered them without holes in the bottom half to keep wet dog stuff out of the van.
They're inside my SUV.