FOA, let's say I am not interested in starting a flame war nor arguing with you or anybody else about jack vs pulse.
- jack and PA are completely different (http://jackaudio.org/pulseaudio_and_jack) so there's no use in listing what PA can and can not do
- jack is intended for audio pro but it can address low/high level tasks without fiddling with upgrades as you claim.
- you run ardour but how many apps are you coupling with it? using jamin? hydrogen? guitarix? synth? well all those apps can be controlled and synced by jack with a high level of complexity in the connection graph. Can you do it with PA (answer to yourserlf)?
- belive it or not, pulseaudio does not address pro audio needs
- debian devs are right in using PA, they must aim at the average user
last: I have SUGGESTED hime to give it a try (killall pulseaudio != remove pulseaudio)
[insert your favourite pet system sound here]