The Vivid has an extra special wi-fi feature for better wi-fi performance.. This is separate from the wifi sleep setting.. Just go to settings, wifi, and open it up so you can see all the wifi signals.. At that point press the settings button on the bottom of the phone and choose advanced.. It's in that menu just under the wifi sleep setting.. Its called "Best wi-fi Performance".. Turn it on! The Samsung's don't have this additional wifi performance setting.. They only have the standard wifi sleep setting.. It will give better wi-fi performance.. If you already have a good signal already you may not notice anything.