I read reviews of a few chargers before settling on this one, and I'm glad I chose it. It takes two controllers, and will have both of them fully charged in around two-and-a-half hours from a single USB port. Much better than having to switch a cable between controllers and charging them individually.
An LED near the connection point for each pad shows red when charging, and blue when "fully charged". There is a slight discrepancy here, though, as the LED always turns blue while the 4 lights on the controller itself are still blinking... so just leave the pads charging until their own indicators stop blinking.
It's pretty solidly built, but like a PSP it's very shiny and shows up fingerprints terribly. Not really a problem, but it can start to look fairly grubby if you don't wipe it over every so often. It's light, so you will need to hold it steady when connecting controllers... meaning that fingerprints build up very quickly.
The only real down-side is that the blue LEDs around the base are very bright, and there's no way of turning them off other than disconnecting the supplied USB power lead. So if your console is in a bedroom, you may not want to leave your controllers charging when you go to bed. A switch to turn off the LEDs would have been nice