I can't really say that the case is perfect but does it's job well to a point, but however if you want to change the memory card, you would have to take the ZEN X-Fi out of the case.
Also the ZEN X-Fi when placed in the case doesn't feel as secure as one might think as the X-Fi can easily slide about inside the case from side to side.
Also if you forget that you have the flap open, make sure that your fingers are placed at the opening where you insert the player in to the case, as the player itself can slide out on it's own very easily.
Pro's:
the case itself feels solid and quite tough to take accidental drops and bumps.
Con's:
The player feels slightly too loose when inside the case.
The player can slide out too easily if the flap is open.
No access to card slot when the player is in the case.