Hi. I don't speak English
Stereo (270.5 kbps):
However --> Figure 2 (Join-Stereo > Figure 1 (Stereo)
Joint Stereo is generally more efficient than pure Stereo (you can read how Joint Stereo works here: http://wiki.hydrogenaudio.org/index.php?title=Joint_stereo) (http://wiki.hydrogenaudio.org/index.php?title=Joint_stereo)). Since you're using a Quality parameter (-V0), the encoder can simple use less bitrate to encode at the same Quality.
Either way, that pictures proves nothing. I would say that the quality of both files are similar, but at such high bitrates both should be transparent.
The point of joint stereo is to decrease the bitrate needed to represent a particular two-channel signal.
Also, we don’t care about pictures. You listen to music with ears, not eyes or any other organ. Number 8 of the rules to which you were directed during registration makes this quite clear.
Forcing simple stereo (-m s) in VBR modes can inflate the bit rate, since it's less efficient than joint stereo. It's that simple.
thx