I used all the above mentioned and for the last few months have been using Dave Watanabe's xtorrent and it's flippin' ace! It's smooth, pretty much bug-free and very quick if your system is up to it and your connection allows. (I'm using 24Mb ADSL but getting 6-7Mb as an average and have achieved very quick dl's on both MBPro and my old but trusty PowerBook.
What's more, xtorrent 1.1 just beta'd yesterday it has some new cool features although I haven't had an opportunity to really check it out yet (I'm hoping that there is stuff like bookmarks available in the beta).
One word of warning tho, to use the real speed of XT you need to buy a license; I think about $18 dollars. It is possible to to run a XT at full speed without a licensce but your up and dl speed is restricted after about 10 mins.
This may seem mean but the guy has built (and builds other great apps) a good piece of software so I was and happy to have given him a few dollars.
I have no affiliation with Mr Watanabe; wish I did! But believe in 'credit where credit is due'.
D DUbyahs blog:
http://www.newsfirex.com/blog/
Hope this is of benefit to people.