that jackd is great, but needs moar dev. I use it for recording via ardour, which is also great. pulseaudio is kind of a pain. I was having some problems with it but mananged to work around them by doing some explicit assigning of devices for clients (read games).

jackd is really good because it can use many backends, including but not limited to alsa. I mostly use it with the ffado backend to connect my focusrite saffire firewire device to record with.