We are actually proud that our case is slimmer than most other battery cases on the market. We didn't want our case to be bulky so we designed our own custom lightning connector that snugly fits the phone: https://cobattery.com/connector
What don't you like about the case's look?
Just kidding. The case looks fine. I'd briefly wonder whether dropping it on the metal connector at the bottom would damage it, and I'd prefer the battery color match the case, but those are just nitpicks.
We have found the metal connector to be pretty resistant. But we have one year full warranty, so if anything breaks for any reason we will send you a replacement immediately. :)
In my opinion, if we can't make money while ensuring people's CoBattery cases works, we shouldn't be in business.