This is faster than the Panasonic 12-60 M4/3 lens, but I don't see the value proposition, even at this price. The 12-60 is less expensive, longer, not much slower, and it's environmentally sealed. To me, that is more versatile.
But I'm also a novice, so I'm not saying one is better. It could be out of pure ignorance that I don't see the benefit, here. :)