Comparing different video qualities on channel9

Channel 9 offers videos in different levels of quality in two different formats (wmv and mp4). Everytime I would like to download a video comes the question...

Channel 9 offers videos in different levels of quality in two different formats (wmv and mp4).

Everytime I would like to download a video comes the question: What offer is should take? So I have made a comparison of all formats. Here is the result:

As Input I used the Rx Workshop Introduction (Rx Workshop: Introduction).

FormatDimensionSizeVisual Rating (subjective)
High Quality WMV (PC, XBox, MCE)1280 x 72058 MB++
Mid Quality WMV (Low-Band Mobile)512 x 28834 MB+
High Quality MP4 (iPad, WP7)1024 x 576140 MB++
MP4 (iPod, Zune HD)480 x 27215 MBo

Both high quality videos are very similar – maybe with a little advance for MP4 – but MP4 is three times larger, that it is not worth.

So for me the two WMV-choices are the right one. If the videos have detailed artefacts (like Visual Studio coding) the higher resolution could be a benefit.