Author's Note: This review will be updated two weeks after the original publishing date in order to reflect the quality of the item over time.
Having said the above disclaimer, I have been using this product a little over two weeks from the original delivery date of 17th February in an attempt to cope with absolutely no electricity in the house whatsoever, save for two wall sockets located in the kitchen (a good ten steps from my bedroom). This power bank would spend the day being charged while I was at work for a good 8-9 hours which I will then be using it to top up my mobile phone battery (an HTC One m7/2300mah) instead of leaving it in the kitchen every time as well as while on the tube.
For the two weeks that I have been using this power bank I have been able to roughly measure its real-world performance. After a fuil charge, the power bank was able to charge my phone from 10% to 100% 4 times in total (with still enough for an extra 20% battery boost) before the power bank itself needed a full recharge. I have yet to test the battery's retention capabilities, perhaps when I get electricity back in my bedroom I will give it a try and update this review at a later date.
Good feel in the hand and has a reassuring weight to it. It feels like it can take a bit of a beating, of course I wouldn't recommend that given the price point of this product but it will definitely survive the rigours of the daily jiggling in your bag among the assortment of peripherals lying around in there. This is coming from a guy who sticks it in my bag in the same compartment as keys, books, a laptop and its charging brick. Not to mention my backpack barely has any breathing room for other accessories such as a power bank so if I happen to drop my bag on the floor or accidentally hit it against a wall or a pole by accident (because I'm a klutz like that) all the items in there bear the brunt of the impact; and this power bank is no exception, but it still functions perfectly. Once again, don't mistreat your electronics guys :)
At the time of purchase, the power bank cost a measly 15.99 pounds. Think about it, 15.99 pounds for a 10000mah battery, even if the real-world performance measures up about 10% less than advertised and it comes with a 2.1A port for high-powered devices like tablets. Not much to think about, I strongly insist you buy this!
This product performs at a level that clearly exceeds its price point, that much I'm sure. I have yet to test other areas of the device, such as the battery retention, but it is definitely a brilliant product for the price! I for one am a satisfied customer and I'm definitely certain you will be too.