I am never happy with the quality or price of commercial rabbit cages, so I made my own and am much happier with them. Problems I've had with commercial (FYI, these are indoor cages housing 1-2 pet rabbits only):
-Hard to clean due to small access doors (I like top access doors or large side doors)
-Paint peels and then metal rusts making cleaning a joke
-Usually no platforms offered for rabbit cages
-Many do not offer enough head room for the rabbit to stretch upwards on its hind legs, let alone to hop around a bit
-I don't require dark housing areas for pet rabbits, but definitely would want a burrow like compartment for outdoor rabbits (my rats do have a dark "underground" nesting area to use during the day, and they definitely seem to appreciate it). Only outdoor hutches seem to have those, and not so much the wire cages
Traits I like in commercial cages:
-Cages that can collapse and are on wheels for easy moving (I don't need wheel locks for indoor use, but those are handy in some cases)
-Cages that can be easily modified, connected, and expanded.