And BitTorrent isn't the company it once was, developing software and protocols with a vision and for a purpose. Just look at what a pile of infested crap uTorrent has become.
On the positive side: Transmission works great!
Edit: here you are. you can still run it without instaing even: http://www.filehorse.com/download-utorrent/7858/
If you don't require streaming, older uTorrect clients are still your best option. If you do, it IS possible to install the recent version of uTorrect without any external adware and to disable all of the banner ads.[1]
[1] http://forum.utorrent.com/topic/81421-321-how-to-turn-off-ad...
Transmission and deluge often max out my bandwidth though, so its not like they're poor performers.
http://www.cvedetails.com/vulnerability-list.php?vendor_id=6...