I have just used my 3 on the weekend.
I used the formation that gives them the 3++ save (3 Wazboom jests + 1 Dakka jet) here is their load outs:
Flyboss: Wazboom - KFF, Teleporta blasta, Super shoota - 190 points
Wazboom - Teleporta blasta, super shoota - 150 points (125 base cost)
Wazboom - Teleporta blasta, super shoota - 150 points
Dakka jet - 3 super shootas -130 points
An anecdotal story:
They were combined with the Great Waaagh Detachment, allowing a Waaaagh each turn after the first, this allowed my Jets to be much more deadly (assault weapons fire and extra shot). I was against Khone Demon Kin which had 2 Helldrakes. I flew on turn 2 and proceeded to wreak everything, I didn't even bother to use the formation giving them a 3++ they all just arrived and each Wazboom nearly deleted a unit each. When the Heldrakes arrived it gave my Dakka Jet something to Shoot at, along with my Lootas. It was a 2000 point game and I was lacking a lot of leadership, but I got into assault nice and quick ,so it prevented my boys from running away. I won the game, even with his units being summoned each turn.