Although my choice is to play the guitar with ardour
(although it's unstable)
I found one reason for instability: LADSPAs.
Before you use a certain LADSPA try loading it into jack-rack.
If it complains that the plugin isn't realtime capable, do
not use it in Ardour.
, because it allows you to record,
play with the metronome and is very usable.
Agreed. I'm very thankful to Paul who did present a stable
version of Ardour at the LAC this year. I immediately started
playing around with it.
Best regards
ce