VLC needs quicker access to subtitles, and they need to search for subtitles on the web, like BSPlayer does it (if they already do this, then it must be hidden very well, and I'm not aware of it).
SMPlayer can search opensubtitles too, it's a GUI frontend to MPlayer which can play every media you throw at it. My other favourite feature in SMPlayer is that it resumes video playback from the position you closed it.
