ZeuSter

k0elw.
Each Long Tone begins with an initial attack , so therefore ecah tone is a chance to practice good "coordination " of the breath and the attack which should be all in "one motion" so to speak.
Also ,it helps your initial attack on the upper register notes , if you crack the note , stop and do it over with a "clean attack" .
Lots of opportunity to practice attacks with long tones.

PH,

I agree 100% with what you said about the "meditative" aspect of playing long tones.