Resolution: theory and practice
Compared to HD/SD material, HDTV footage has a much higher resolution and therefore contains far more data. These finer nuances in movement allow much greater precision in stabilisation. Consequently, it should theoretically not be possible to stabilise a VGA sequence with a resolution of 640×480 px as well as an HDTV sequence.
Moreover, a clip in progressive mode can always be analysed better than an interlaced clip.
This means that HD not only provides the best possible image; its potential regarding the removal of camera shake is also better. This can be measured and formally shown. However, in practice a stabilised standard DV clip shown in interlaced mode on a TV screen may subjectively appear to be much calmer than a DV clip viewed on a computer monitor.
To sum up: although theoretically there may be factors that enhance movement analysis, the subjective impression of a result is ultimately what counts. Which is why Mercalli lets you set some options according to your personal tastes…