In our opinion, both the wired massagers and cordless units are useful. Which unit you should get depends upon your exact needs and preferences. If you want to use the hand massager at home, you can use a wired hand massager or electric hand massager. This way, you will be safe from charging the batteries most of the time.
Conversely, if you travel a lot or want to carry your hand massager at your workplace, then wireless hand massagers are ideal for you. You can also use and take them on your vacation. So, before buying a hand massager, figure out how you will use the device.