Advanced Gtk+ Sequencer uses a simple and intuitive latency strategy. You may obtain some additional latency to solve rhythmic issues. This takes only effect for starting not runtime latency.
Is calculated as follow in [Hz]:
1.0 / samplerate * buffersize
and gives you generic latency
Is calculated as follow in [Hz]:
(1.0 / tactrate * buffersize) % tactjiffie
and gives you startlatency
An audio signal will be played after generallatency + startlatency.
The GUI has a reaction time of generallatency.
Delay notifies about time spent until next attack and has no more meaning.
Attack tells you where to start playback and is preferabely 0. Since you can't avoid balancing of the relaying OS.