I've always used the built-in recorder to capture my coasters however when it comes to other games, etc I have always used Fraps. (Don't bother with the trial IMO)
As well, what's your rig like? If picture quality, frame rate, etc at that resolution are not what you expected while using other recording applications that could be the effect of your computer providing inadequate processing power.. because it's old or something haha. If that is the case than you should just use the built-in recorder because it will automatically record frame by frame (although it takes longer) to ensure maximum quality and smooth playback. You computer may have difficulty playing the uncompressed video, making it seem like it's just a crappy recording.. Just convert the video to a popular format and all is dandy.