I am sure I am in the minority, but avoid AAC multi channel encodes as much as possible. It really makes no sense for anyone. Most home theater equipment does not support it. AC3 or eAC3 are supported by nearly every device natively. AAC does not work over SPDIF or HDMI ARC without reencoding. All that for a slightly lower bitrate? No thanks. Plus most are likely encoded from a AC3 or eAC3 so they will sound worse than the native version.