I got the PowerBear 7500mAh battery because it seemed to have the most reviews on Amazon. I find it's size and weight to be very reasonable, no issues holding it or keeping it in my pocket. Looks quite nice too. The battery is the standard size so it doesn't cover any antennas. The back cover + tpu case combo is far better for protecting the battery than just a tpu case alone. They are both great quality and a perfect fit and I like the feel of the honeycomb exterior. Battery life is what you'd expect, not as great as a 10000mAh, but still plenty for my use case. Even came with a screen protector.
Was hoping to get a ZeroLemon, but they are rare and overpriced now. I'm very satisfied with this PowerBear anyhow.