[LAU] Jack 1 vs. 2

This subject seems to come up occasionally... What is the current best practice with regard to Jack classic versus Jack 2? It's usually said that Jack 2 is optimized for SMP, but it's hard to find a machine these days that isn't SMP. Maybe the two projects are merging because of this? Because, Jack 1 hasn't gone away. In fact, the only version of jack-audio-connection-kit currently in Gentoo (no overlay) has a version string of 0.125.0-r1, and I presume that's Jack 1. I've got a local overlay with 1.9.12 that I've been using, so I can fight this of course...but should I? Is everyone being advised to move to Jack 1 now? For what it's worth in deciding, I prefer not to use dbus for control (or for anything at all, when I can avoid it), and I'm using QJackCtl as a frontend.