Its hard to say if this charger is good or not, I'm kind of in the middle at the moment, on the good side it looks great being simialar in size shape and overall look to an iphone, it arrived quickily and was fully charged on arrival, i used it to charge my HTC sensation xl from flat which it did easily, i then used it to charge my wifes phone as well which it did before the charger itself then ran flat. It also come with loads of adapters for different phones and devices which is ace.
Now for the problem part, once it ran flat I decided to test how long it would take to fully re-charge from flat on solar power alone. Its been 3 weeks now and its still only 3 quarters charged and doesn't look like it will ever make it to fully charged without being plugged into the mains. You also have to bear in mind that this 3 week period covers the really hot weeks we had in the UK over march when temperatures during the day were in the 20's, in addition I put it in my kitchen window which is south facing and gets the sun all day, in other words probably the most optimal conditions you can get to charge it with solar power and it still hasnt managed a full charge. Over and above this the bulk of the charging took place on the really sunny days (you can check with the led charge indicator) on the days at the start and the end of the 3 weeks when it was cooler and over cast the device hardly picked up any charge at all. I even tried putting it outside thinking maybe my k glass windows were blocking the uv light it needs to charge but this didnt make any difference.
In short the decice is great for re-charging your phone when out and about and in this respect is really usefull, just dont think of it is a solar charger that can re-charge itself using sunlight alone in a few hours, thats never going to happen. I think its probably best to think of this device as a portable power source for your phone that is charged off the mains/usb but can also be topped up with solar power if needed, do this and you wont go wrong.