Bought this for my trip to Japan. Not disappointed at all. I was afraid it wouldn't be enough but this guy lasted me multiple days/charges so I only needed to carry one power bank. It charges super fast and hold quite a bit of power.I did a couple of tests on it. I was able to charge my Samsung Galaxy 7 tablet almost 70% from 0% on a full power bank. If you aren't familiar, this tablet takes about 3-4 hours to charge with the OEM charger and holds a lot of charge. To be able to charge the tablet up to 70% is phenomenal. I also found that it was able to charge my phone 10% in about 10 minutes. I'm not sure how this tracks on other phones since I'm still using the Pixel 3 XL and its battery is pretty bad now.Regardless, it still holds a quite a bit of power. There's not much charge loss over time because it still had the same amount after months of non-use. It charges fast which is good for travel or emergency use. It is slightly heavy but that's to be expected for this performance. With the little digital display to let you know how much charge is left, this is a great product to have around.TLDR: Slightly heavy but performance is amazing. Digital display means you'll never be surprised by an empty power bank.