Works great in Opera 9.27 OS 10.4.11 (PPC).

One question though: does the higher-quality video have a higher resolution than can be displayed in the the embedded window? i.e. is there a loss of quality associated with not being able to full-screen Quicktime videos within the browser? (As opposed to the embedded flash player.)

Unfortunately I don't think there is a good way to fullscreen an embedded QuickTime movie. Perhaps it could be popped up in a new window, but I thought this inelegant. It is possible to easily modify the bookmarklet to make the movie larger, but this ends up overwriting other parts of the page; it doesn't rewrap around the enlarged video. Perhaps some more creative CSS modification could fix this, but I didn't look in to it enough to find out. One side benefit is you can simply save the movie from the menu in the QuickTime plugin, then watch it at fullscreen in QuickTime player.