I'm experienced with Lipos in RC-Cars and i wouldn't use them at point blank in my face. I've seen then going off on no reason in cars and that is really a spectacle. But that's only my opinion. I think the LiIon
batteries have power enough for all
devices so far. And they are far more saver to handle.
At least if you're building your own devices you need a spezial loader with balancer to load those cells and you have to be aware of their inner status at all time. Lipos are far more reactive then LiIons.