If playback is on pc, you won't get full screen unless you tell the player to show full screen. Then it may be pixalated because it will have to stretch the video. Even if you render @ 720x480, you won't get full screen if, let's say, your monitor is set to 1024x768 & you don't tell your player top show full screen. Also be mindful of the templates as some of them use half resolution.