I see lots of heads nowadays with the Machete. Everyone I know who has one really likes it.
I went with the Mod Rocker this year and its a blast. My first "rocker" board and it was a really good choice. It's still got enough stiffness that it isn't really soft. I can carve it like I carve my cambereds, but I can still get buttery when I need to. It's a breeze on jumps. Very stable, compared to other rockers.
I'd say it IS considered rocker-flat-rocker. Read the tech on it - the middle is very flat and turns rocker just before the contact points.
That is pretty much exactly what I'm looking for. I want something more playful without sacrificing too much everywhere else.