I said that I wanted to be proven wrong with the new Panasonic 42.5mm lens, and I have been... at least a little.
Lenstip, one of the websites that reviews distortion based on uncorrected raw files, has posted their review of the lens and it is very positive. The lens is very sharp, nearing the performance of the Voitlander 25mm and the Olympus 75mm. Like those lenses, its distortion is very low, which is a first for a Panasonic lens.
It's not a perfect lens, though. It has some extreme longitudinal aberrations and its vignetting is high. The latter problem wouldn't seem extreme except that of all the problems that a crop sensor should face, vignetting should be the least of them.
But it is interesting that the article compares this lens to the Voitlander 25mm and the Olympus 75mm. Both of those lenses performed better and cost a great deal less. That price makes what should be a competitive lens into something that is still competitive, but not terribly impressive.
As I said, this does little to change my thoughts on the lens. It is significantly overpriced. Even with its OIS, it shouldn't have cost more than $1,200. That said, it is at the very least a good performer. Once the price comes down to something reasonable, or if you can find one on the used market, this could be an excellent purchase.
Until then, your money can be spent much more wisely elsewhere.