Honestly I have yet to try one. Even after the point drops it's still hard to fit everything I want into a Coalesces list. I really want to try them out though...
I have, but only against a small group of skeletons and if you get some half decent rng you can wipe pretty big chunks of infantry of the map plus ahving the skinks help in combat makes them not totally useless as a melee unit, but I kinda wish the models looked more like salamanders though. Edit just played against orks melee attacked three trolls and killed them near immediately..... it seems I underestimated the fire puppy
I'm still wanting to draco drop a squad of them at 9" , to use that 12" range secondary attack its kind of weird rules but what a juicy profile. if you manage to hit a charge after all the better