In case anyone is still using the ad-plagued bitorrent.com client:

Lots of features, easy to use.

For Windows users I'd recommend Deluge, because its interface is more like uTorrent but without all the adware and plus it's open source.

I'm a fan of client-daemon architecture, such as Tmux/Screen and IRC bouncers.

With that in mind I can recommend Tmux/Screen + rtorrent (daemon, ncurses) [1] + flood (WebUI) [2] for if you don't have CLI. Works well in Docker.