It seems fun for a short while

I purchased this item with the Links Crossbow training, thinking that it would be something that adds value to the games that use it. (Resident Evil UC)

The unit is just basically a plastic case that forces you to hold the Wii Remote and nunchuck a certain way. When you set it up, you have to wrap nunchuck cord a certain way or else the bottom of the unit won't snap close, so every time you use it you need to spend at least 1 min or 2 doing this unless you leave a nunchuck in the unit or leave the nunchuck out of the unit and use your left had for the nunchuck like normal.

There are a few games that have modes that are designed for the unit which really just maps the controls different so that its easier to use this device. I would guess after the House of Dead there may be a few others that support it but it's not going to be a must have option for developers to put in the game.
I found using the unit harder to use and less accurate then just using the WiiRemote. After about an hour or so of playing, I found that the unit would rub against my wrist uncomfortably no matter what I did to adjust unless I took out the nunchuck. My scores in Resident Evil and even in the Zelda minigames are usally lower when using the WiiZapper. Also any action that requires you to shake the Wii remote is much more difficult when you have to shake this whole unit. I wanted this to be good, but at the end of the day it comes across as more as a novelty. I like light gun games and I may try a third party option.