I had the Duracell powermat for my 5.
Pros:
-It generally performed as advertised.
-It came with a detachable battery. I prefer this setup to most of the battery cases. It was half the reason I bought it. You only need to attach the battery onto the back of the case when you need a charge or you know you're going to have a long day away from a charger. The rest of the time, you can leave the added bulk off. The battery can be charged by laying it next to the phone on the powermat.
-Price. I think I paid about $60-70 straight from Duracell, cheaper than most battery cases.
Cons:
-The powermat can be a bit finicky. If you don't lay the phone down correctly, it won't charge. There were a few times I woke up in the morning with an uncharged phone.
-If you ever want to charge it normally/in a car, you have to remove the bottom of the case.
-It isn't compatible with most headphones. The dopey way the bottom of the case sits will only allow a straigh, narrow plug. I had to remove the bottom anytime I wanted to listen to music.
-The case is a bit flimsy. I never dropped mine. I assume it would protect the phone okay, but I wouldn't be surprised if the bottom of the case broke after one drop. If that happens, the whole thing is useless.
-Similarly, if you lose the bottom of the case, it's worthless. That was the end of mine. I handed it down after I got a 6. I don't think it lasted 2 weeks under the new owner.
It served its purpose for me. It was fine, not ideal. I think that technology is best on phones where it is built in. It's too much of a hassle otherwise.
Edit: It appears they have redesigned it and raised the price back to normal of $120. so this review is pretty much moot
