There's very little chance you actually tried all the presets. I don't think there's a CPU out there capable of doing live encoding on placebo right now. :)
The difference in quality will show with lower bitrates. If you're only recording locally, you should just use the recording presets.
http://obsproject.com/forum/resourc...lity-recording-and-multiple-audio-tracks.221/
Okay my bad. I figured that Veryfast does it just fine and anything lower than that makes the video choppy. Since I'm recording for a couple hours should I put it to superfast as the CPU might be under load over a longer period of time? At Veryfast it goes to 92% CPU usage. Would it be bad to leave it recording for 8 hours and the CPU usage being at 90%?