My only problem with Jack is that Firefox (and Chrome too, afaik) absolutely insists on using Pulse, so you have to make both play nice if you want to use Youtube while working on music (which is actually pretty common). This can be a bit of a pain (funny things happen after suspend/resume). Still it's so useful for music/sound production, I put up with it :-)

Yeah I can relate to that, I start jack with qjackctl and run this post startup script "a2jmidid -e & pacmd set-default-sink jack_out "

Fair point, I didn't know that.