Downloads of one giant file are less reliable - more of a chance someone will download 5GB and then have to start over because of corruption. Torrents aren't much better; I downloaded some 25 GB video of a train in Norway and 90% of it is unviewable.
The best way to do this would probably be a multi-part rar.
If your torrented video was corrupted, it's because the original file was corrupted. Your torrent client would have thrown away anything that's different from the original.
> The best way to do this would probably be a multi-part rar.
They already offer multiple-file downloads. The compression algorithm isn't going to change the fact that multiple concurrent downloads fail.
rar is often employed more as a packager than a compressor. For instance, if you have a 5 GB file to offer for download, you split it into 7 parts with rar and offer it as a self-extracting .exe, like they are doing here for instance http://www.microsoft.com/download/en/details.aspx?id=11575
As for the file being corrupt, I suspect something else may have been going on, such as bugs with torrent clients. I don't know why the original source file would have been corrupted, as it was supplied by the maker of the film.
The best way to do this would probably be a multi-part rar.