Not for nothing, directly below that they indicate they HAVE tested it and give some numbers...
But sheesh...this has to be one of the ugliest things I have seen since, well, since, I dunno...I can't remember the last time I've seen something this clumsy and ugly...for 279.00 which you have to VELCRO or TAPE to your iPhone...
UM...I don't think so. Luckily, I've never had a signal problem with the iPhone.