In operation, the device is only slightly warm despite very high output power and never hot. It stinks nothing and the device provides its work. I tried once with a Profiteck meter to measure, because I generally do not trust the manufacturer's specification, the actual performance.
If you load a smart phone so there is no difference to z.Bsp 0.7 A or 1 A charger. (Showing 4-5 watts wasted) However, when a Tablet PC or even a Power Bank invites thus, this charger has yet all other reserves and then pulled out of my socket instead of 4.3 watts almost 13 watts. I see the advantage of this device is that it is simply safer by the possible high performance and the slightly larger type (without being hot) boost performance devices.
Over the long-term experience, I will report.
Update on 07/16/2014: As you can see the date of original review, I have been part of a good six months in operation.
I can still only positive things. All (my) devices are loaded and there were no problems so far. I still noticed the following: When I boot my Power Bank (6000mAH) to the USB power supply of my Google Nexus 7 (the power supply has 1.25A), I need about 6 hours. With the 2.5 A power supply described in this do I need for the same charging just under 4 hours.