I often get things wrong, especially on #jack on IRC. But it irks me to see people continue to make this claim about jack2. Let me reiterate: the normal version of jack2 does not and cannot use multiple processors if the data flow is serialized. Mutiple processors are only used where there is parallel flow between clients. Although this is not unheard of (e.g. two synths flowing into a DAW), its unlikely to be the common case for most users.

Many people find jack2 to be "more stable" because it does not zombify clients in its default mode operation. It allows clients to be "late" by a substantial amount, which can result in clicks and pops in their "apparent" audio stream, but doesn't cause the server to kick them out in the way that jack1 does. One way to look at this is that jack2 is more tolerant of programming errors and system latency than jack1.

--p