Put some practical thought into what it might be like to use that, before you buy it.
1. You normally aim on Wii through the relationship of realtime visual feedback and adjustment of the on-screen reticule. NOT by looking down the line of sight of the remote
2. Think about how you normally aim the remote. It is slightly tilting up? Now imagine holding it inside the gun shell. If you aimed the "gun" at the screen, would the reticule be higher or lower than normal?
Does UC even come with the kind of calibration options offered in Twilight Princess?