I occasionally use Ventrilo for comms with my BF2 clan. Client was cake to set up and the quality is pretty good.

My only experience with TS was over a year ago and I actually think it was more down to my old screwed HD than the app itself.

So I voted Vent, but have no real preference either way.

Quote from ColeusRattus :

mumble all the way.

http://mumble.sourceforge.net/

Have you or anyone else tried this? Any opinions on it?

Cant really find the differences. Its probably because i only speak in them. Nothing else :P No programing or stuff. But i voted ventrilo cause i love the bind option. Muhaha !

I've gone from Roger Wilko to Teamspeak 2 to Ventrilo. It's still Vent all the way, as even with the highest codecs the quality of TS2 is arguably a lot worse than Vent running at high quality codecs.
Sure, bandwidth use increases (quite a bit with proper codecs) but with a broadband connection it will never become a problem, unless there are more applications straining your connection.

It seems to be an endless debate though, there are some people who find the Vent UI incomprehensible, and the quality difference non-existent, and then there are people like me

Quote from [RCG]Boosted :

duh, never heard of it but im always open to something new.
are u able to host a server on ur pc and join it by urself just as u can do with TS? then i might give it a shot

It is It lacks some importent features though, like voice activation volume etc.

Quote from avellis :

Have you or anyone else tried this? Any opinions on it?

My Red Orchestra Clan Project TWilight uses it. allthough it has some hickups, like sudden lag spikes, it is definately worth a try, if you are willing to spend some time and thought into setting up a server.