Despite hating almost all the design changes in iOS 7, i have to say the wifi performance is drastically improved in low signal areas. At work I'm in a part of the building which purposely does not have wifi or cell signal, but somewhere nearby, it is allowed. Under iOS 6 with an iphone 4, i could barely get notifications in one corner of the room, and in 90% of the room, no signal at all. I could never download email, apps, or load webpages. With iOS 7, i get wifi everywhere in the room now. I ran a speedtest, which was impossible under iOS6, and got 35 mbps down and 5 mbps up with a ping of 15 ms in a place that's not supposed to get wifi! In reality, the phone doesn't download anywhere close to that, I would estimate it to be closer to 0.3 - 0.7 mbps when downloading or updating apps, but it's better than nothing. In high wifi signal such as home, I don't notice any difference. Battery life seems better than before, but that might be my imagination.