I am very impressed with this Apple watch charger. It is great for travel instead of taking another cord with me to get tangled. Instead, this is compact and easy to take along. It plugs directly into a usb port and the watch lays on top. I've been using this for a couple of months and it charges great and does not get any hotter than my orignial apple charger.
One caution. It does not work with usb ports built into outlets that face up and down. Then you can't rest the watch on top.