i'm looking into a future cage upgrade for when my girl is an adult and so far i'm conflicted between 2 npi cages from npicages.com.

theres the standard 36" (which i was originally gonna go for)...



& now theres the 36" stackable (which i'm liking better)...



the main thing i'm looking for is a cage that has a basin-like bottom so it can contain substrate.
the standard cage looks like the bottom is flush with the opening and if it is then the substrate would fall out every time the cage is opened.
i cant tell very well if the bottom in the stackable is the same way.

does anyone know what the deal is with these cages?