It's not so much their rules on paper, which are good, but not "oh to the fainting couch" good. It's how they interact with the current 40k metagame out there.
As I'm sure we've all seen the rise of mech is still loud and proud and many armies (I'm looking at you IG) routinely field 10+ tanks in standard sized games. In this type of environment I find there is not a purpose built surgical tool as effective at breaking up those pesky multi-layered vehicle fortresses as the Mawloc. It's almost to easy. Pick your target as close the the epicenter of the massed enemy parking lot, roll the scatter dice, and let the distraction begin.
If you're unlucky you may only kill a handful of infantry or shake a very lucky couple of APCs. With good rolls, you can easily send entire tank squadrons or packed elite infantry squads back to their gaming cases.
In any case you have certainly drawn the focus of the enemy army onto your sneaky Mawloc for a good turn, leaving the rest of your forces a bit of breathing room to go about their business of winning the game.
There is however that little irritating question of whether you can purposely position the Mawloc onto enemy models in the first place, or if you must put it in an empty position and hope for a scatter.
Its almost like we've seen other vague issues like ths in the Nid codex in other locations. Hmmm, tricky stuff indeed...
