Ever since I got my iPhone 5 on launch, videos from any source have been extremely slow to load over wifi. I speed tested my wifi which is a 35mbps connection and was disappointed to see I was only getting 9mbps down. If I download a large file or use airplay, the speed of my wifi on the phone increases drastically. I've tried testing others' wifi connections and the problem exists while connected to them too, leading me to believe this is an issue with the iPhone. The problem is shown in this video that I found (link). I'm just putting this out there to see if anyone else is having this issue.