No, but I too am looking at perhaps buying this lens. Please let me know how it works out once you get it and try it out. I know that Panasonic uses both Leica and Lumix lenses. As they are an electronics company, I would think they use an outside lens maker for their own brand and Leica for you know. I am sure others know for sure.
I did a side-by-side on this vs the oly m. 9-18mm, and I felt overall the Panny was slightly superior in overall image quality, worse on size and weight, but better in build quality and "feel". The difference in image quality I felt, would not be noticed on day-to-day use.
However, I LOVED the ability to go down to 7mm, the extra 2mm at this focal length is significant and allows for very interesting compositions you can't get at higher focal lengths. 7-8mm seemed about as wide as you can go without obvious fisheye look.
Obviously, 7-14 compliments the kit lens nicely, although I found the oly at 18mm meant I didn't have to change lenses when I need to zoom in a bit, such as transitioning from single to group shot.
I am not crazy about f/4, would like some more stops, but in practice you are so wide angle you really don't see the grain because it's so wide. Showgirl picture is 1200 ISO. Even as 8x10, it's not a factor.
On both lenses, be careful of putting people at edge of frame under about 12mm as the distortion can be less than flattering. Vignetting is minimized if you don't angle the lens away from the subject. Pioneer Hotel photo shows the distortion I am referencing. On the flipside, this lens can cover from floor to ceiling on Fremont st... comparable to a typical basketball court, if you've never been to Vegas. Huge range!
I ended up buying the Oly 9-18. While I really wanted that extra 2mm on the Panny, it was strictly price that made my decision for me. That said, I really like the super wide and feel either is a great choice.