Just wanted to add something to this. The TYLT VU 3 Coil QI Charger is also nice, it's more heavy duty, only downside to it, well the only 3 downsides to it are.
1. Proprietary charger, not a Micro USB like the AI6
2. Constant trickle charge after charging is complete. Where the A6 shuts down until the phone drops in % and then turns on only when needed.
3. PRICE. It's almost double the A6.
To be honest the A6 looks like a Rip Off of the Tylt Vu, but frankly I love the A6 for the price and what it does. I have also never tested the TYLT VU with an OtterBox but I would guess it would work as it's also 3 coil.
Just to add to this. Finally got some specs on charge time. With the Samsung Fast Charge 2A Adapter. I get about %30 per hour battery charge using wireless.