And where do you get these .srt files from?
Do enthusiasts interpret and enter them all in for you?
Or are they OCR interpretations from a DVD vobsub?
The latter requiring significant manual correction.
The way I see it there is no decent mechanism available today for subtitles, however, what you have described is pretty nice, as long as you can get the .srt files from somewhere and can massage the video into the correct forma.
IMHO there are still too many gaps in the subtitle arena that need to be filled by the content and media suppliers.
Cheers, Ed.