I wouldn't bother with the healing alone, but it's my wife's first MH game, and I know that if Purple Ludroth and Gigginox poison me a lot, she'll be getting poisoned too. So I might as well be able to Antidote us all while healing.
I figured that for Sonic Waves I could try keeping the notes up and ready to go at all times. Does the effect take place right away, or after the song is done playing? What's the area of effect like? If they need to be right next to me, yeah, it's probably not going to be helping with Diablos...
It would be badass to play Sonic Wave near a bunch of Delex and have them spring up, though.
I'm mostly theoryfighting - I'll have a more educated opinion once I get to try the weapon out.
When do you Sonic Lagombi?
Well, this is in all in the context of playing with my DS-using wife, so Negate Stamina Use is a prerequisite. Otherwise I probably wouldn't bother at all, since I'm good at managing my stamina.