So far, I am satisfied as it charges both my phone and watch simultaneously in satisfactory times. It is small and convenient and does what it promises.

It is the top choice for those who have devices that can be charged via a USB charger. I use it to charge my MacBook, iPad, headphones, camera, etc. Charging times are much better than the standard chargers of the devices.
Very important is that it does not heat up like a device and that it significantly reduces the number of necessary chargers that one needs to have with them while traveling.
It is lightweight and its shape (basically a square card) serves for discreet storage even in a pocket.
Finally, the name of the company is also the biggest guarantee.