On windows I used BitComet torrent client which has great feature - download files in preview mode so I can see movies right away.
uTorrent declared to be able to download files in preview mode but in real it doesn't.
Which torrent client has real preview mode?
qBittorrent developers claim to be producing a "free" alternative to uTorrent.
One of their features is Sequential downloading (aka "Download in order")
However, this feature is with a health warning:
Attempts to download the selected torrents in sequential order.
Torrent pieces are usually downloaded in an optimal order which
maximizes speed and benefits to the swarm health. Downloading in
sequential order is useful for preview files. However, this feature is
against Bittorrent protocol recommendations due to its negative effect
on the swarm. It is thus discouraged to use this feature. A more
detailed explanation of why this feature is bad is available here
