Setting up the wireless nunchuk is easy. First, you'll need to make sure your Wii remote is on and connected to the console. Then, attach the tiny adapter to the base of the remote (where you'd normally clip on the nunchuk's wire) and turn it on. Turn on the wireless nunchuk and press the sync button on both pieces. A solid blue light on both ends means you're all set. (It's worth noting that you'll need to sync up once per gaming session--every time you cycle the Wii's power, you'll need to resync the Kama.) The receiver adapter piece does add on about an inch to the Wii remote, but it doesn't compromise comfort during gameplay. After a few moments, we forgot it was even there.
While we didn't have much of an issue getting our nunchuk synced, we did encounter a couple of instances where we had to resync our nunchuk because it seemed to be "stuck" moving in a certain direction. Just powering off and on the receiving adapter and nunchuk seemed to do the trick. Not to worry, however; this seemed to only happen when you first sync the nunchuk, and never affected us during gameplay.
We tried the Kama out in a number of games including Mario Kart Wii, Super Mario Galaxy, and Resident Evil 4: Wii Edition--all performing just as well as the original nunchuk. It was nice to have the freedom to place the nunchuk wherever we wanted, not worrying about being tethered to the Wii remote. However, other than that convenience, there doesn't seem to be a whole lot the wireless nunchuk has to offer.
We liked the Kama Wireless Nunchuk. It performs just as you'd hope it would, a sporadic glitch here and there notwithstanding. Available for around $35--about twice the price of a wired nunchuk--it's more of a luxury than a must-have accessory. But anyone who's felt constrained by the cable of the existing nunchuk can buy one knowing that it works as advertised: you won't be missing your old wired nunchuk any time soon.