It's a shame it's not ultra fast but for like this guys says its ok as a feature.

The WiFi video link is very detailed and smooth believe it or not. But of course the catch with WiFi is that it introduces a 4 time delay lag. This is a shame but for setting up a shot it does the job! I think for the uses this camera has, you don’t need realtime monitoring any way. Just the ability to set that shot up and monitor it remotely with no cable is pretty cool for a free add-on. The app is free in the App Store and the firmware update is on Go Pro’s site here.