What I want the system to handle is mainly a brand new shiny MuSE but also
Ardour, LMMS, linuxsampler and a few other software.

Avlinux is centered around Ardour, so it has always the v last release. In AVLv3 Linuxsampler and Qsampler come pre-installed as well. No sure about LMMS, as I don't  use it at the moment.

- Ardour 2.8.4 w/ LV2,
- VST(i) Support via FST 1.8 or DSSI-VST 0.8
-  linuxDSP JACK Client Plugins (most beautiful GUIs:-)
- Linuxsampler 1.0