ipad pro battery life

Been looking around for power banks from my iPad Pro and wondered what people suggest? This come up top on Amazon and they look cool, anyone tried them, plus it uses the lighting lead to charge itself so no need to carry a micro USB lead..? Says its a worlds first too. Besiter Mercury 10000mAh...

For those of you who have picked up the iPad Pro, what are your thoughts on the battery life? How does it withstand heavy use and how quickly does it re-charge. I am interested in knowing some of your hands-on thoughts as it deals with battery life.