I don't know what you want to use it for, but I couldn't really get it to work for what I intended. I was trying to add subtitles in VirtualDub for encoding to DivX. Just couldn't get the filter/plugin to work; it wouldn't open my .idx or .sub correctly.

That doesn't mean it was utterly useless, though. It comes with a very useful utility (Subresync) that easily edits the subtitles and converts between several different formats (srt, sub, smi, psb, ssa, and ass).

This was necessary because I ended up using SubRip to get the titles into a nice textual format but it only saves as .srt. I used Avery Lee's own VirtualDub 'subtitler' filter (available at http://www.virtualdub.org/virtualdub_filters) to add them in VDub and it requires .ssa.

Voila! Subresync allowed me to convert between these two, and also format the text where and how I wanted it.