Kangaroo leather tends to be very strong, but also very thin. It makes GREAT wallets, but it has very little rigidity.
On top of that it tends to be at least twice as expensive as cow leather (even here in Australia!) so it's only worth using if it's used to it's potential.
In my experience, it wears in to be very nice and soft. I have a loop holding my car ignition key, and holds everything together so nothing jingles.