You have only one review in you profile and it's complete phoney BS you work for the company man!
I just received my IMP500 and it *barely* charges the iPad at this rate it will take a whole day and it is no surprise here is why:
The output is 600mA. It states that in the paper napkin of a manual. A computer's USB is 500mA and is the bare minimum needed to charge an iPad. The iPad charger that comes with it outputs at 2A (2000mA). By comparison, the iPhone charger outputs at 1A (1000mA)
There you have it just the basic facts, no opinions. You can form your own.
Yes. The older ones show it's not charging but it is. It flows 5a when the iPad uses 9a so it IS charging but at half the rate. NOW they have an adapter so you will get the full charge speed. It's still the best on the market. I HIGHLY recommend the 880. It fits easily in my jeans pocket and is the strongest out there. There is one more they sell that is more powerful but they were sold old when I was buying mine.