I played my first game with this army earlier this week against Luke. Luke couldn't find his Orks so he used a Tau force with a couple of Devilfish with Tau Warrior units inside, some Battlesuits (HQ), Stealthsuits, three squads of Kroot and two Hammerheads. Surprisingly, I won the game fairly comfortably with my close combat scouts performing admirably - they fought off some Warriors, survived two units of Kroot shooting at them, helped my Terminators land on target, killed a unit of the Kroot and still held on to an objective.
So, with my faith in Scouts restored, I have finished painting my second unit of them, this time with them armed with shotguns. In future games I might try mixing these with the close combat scouts so they get more chance to kill before they assault.