Is there one to match utorrent? That is: light, speedy, powerful?
Like in the case of audio players, at the start I was puzzled by the fact that people use very weak programs (Transmission) or, otherwise, some that are almost bloated and very memory hungry (Deluge and Vuze - the latter is - God forbids - even based on Java!).
I find Bittornado bizarre and still heavy. Ktorrent seems more decent, but still makes itself uselessly noticeable in the list of memory eaters .
All these are usable if you really need to, but I wanted better and I found them: qTorrent and Flush. They have a familiar utorrent-like friendly look and are good and lighter.
Qbittorent is in the official sources.
sudo add-apt-repository ppa:konishchevdmitry/flush
sudo apt-get update
sudo apt-get install flush
Flush is really light.
Another cross-platform application in this family is Tixati. (Somewhat heavier.)
The linux version of utorrent has to be used through the browser and that is cumbersome and heavy. I used the Windows version in Wine and will not repeat that feat.