Ahh, you hadn't mentioned in the initial post that you were doing this specifically for local recording. That does make a significant difference in what settings you will use.
Most here (myself included) are more concerned with the livestreaming side... good livestreaming results are all about using the constant bitrate you have available to manage the tradeoff between image fidelity, motion fluidity, stream stability, audio clarity, and game alacrity.
When recording locally only, you can more or less 'crank it to 11' for all settings, as your bitrate is only really limited by your hard drive's throughput (MB/s rather than Mb/s) and CPU processing. So yeah, go nuts. Bitrate/buffer to 320000 (40MB/s write, most HDDs can swing that easily). Drop the x264 preset to Fast (assuming it doesn't bottleneck your game). AAC audio? Max out its bitrate. 60fps (or 90, or 120 with the 'allow' checkbox set), and all the bells and whistles.
Livestreaming, you need to bear your bitrate (and your viewers' bitrate) in mind at all times. Locally recording, editing, then uploading a dead file? Not a concern. So yeah, if you're just recording local? Set all options to VERY YES. Unfortunately, there is no ability to record locally, and stream at different rates (yet?). So it's either going all-out for a local, or living with the quality of the streamed version.
Can help tune your streaming settings more though (still not clear on if you're ONLY recording locally, or trying for a hybrid local/stream).
