Last game I used these guys they got annihilated. Turning up behind your opponent's lines is great, especially with Snikrot with them...UNLESS you come in next to some Tau battlesuits armed with flamers. Not good. The whole unit was burnt to a crisp in one go. I know they are essentially a suicide / distraction unit, but man that was too fast! I will choose my target a bit more wisely next time. They may even just go for a potential Linebreaker role. I added two Skorchas to the unit for frying stuff when they come on. If someone is hugging the back of the board in cover, it could be awesome.
The head bitz from Forgeworld are just too cool. The backpacks are great as well.