Let's not diminish the full value of the case here. It's a beautiful case, and I've owned a few authentic Vapor Pro for the 4/4S. It's probably the best looking bumper case I have seen on the market for the iPhone 5 currently. Unfortunately, the whole reason I upgraded my 4s to the 5 was to utilize LTE. I'm located in the SF Bay Area, and I have AT&T service for some background information.
After about a week of testing in SF and cities in the near vicinity of SF and South Bay, I've noticed the following with the case: There is a definite signal loss of 1 bar on average. If I am in a poor service location for AT&T, let's say 1-2 bars with the case off, then I will drop to 1 bars maximum or No Service, or Searching. If I had LTE consistently capable at a location without the case, with the case, I would have constant fluctuation of LTE and 3g/4g or complete loss of LTE. (More info below)
In a majority of the locations I have tested it, If I had LTE capable without the case on, with the case on the signal would be erratic. I would go LTE to 3G/4G constantly and the speed difference would be extremely noticeable not having LTE consistently. In the end, because of the fact that I could not consistently get LTE with the case ON, I returned this case to Draco yesterday. To be honest, if you are in a location without LTE, having this case on or off is pretty negligible toward the service. Unfortunately for me, since I am in a LTE city, having this case on prevented me from using LTE and the phone. For a $100 case, this was unacceptable for me.
If you don't have access to LTE though, this is a beautiful case and I don't think the signal loss is bad enough to not use it. (I had purchased the Metro Black one) I had no problems with call quality outside of the poor service areas with the case on. AT&T call quality is only average in the SF area though its LTE speeds are phenomenal here.
Hopefully my review will assist people in making their decision when purchasing this case.
Bullet Points:
User in a city without LTE: Get the case, it is an amazing, high quality and beautiful bumper.
User in a city with LTE: Stay away, it will make LTE useless and inconsistent with the case on.