Before I bought it, I had some concerns about whether I should go directly to the corresponding Leica lens range with triple the price. I have tried several lens kits in various systems. I sold them straight away to get better ones. Luckily, I don't need that with this one. Very good for its cost and I didn't feel lacking anywhere (later on, I also tried the Leica lens from a friend on my camera. Better in low light due to aperture, but only there. I didn't see any noticeable differences in photo quality at apertures above f/3.5).

Although wide-angle lenses often compromise image quality (sharpness, geometric distortions, etc.) compared to lenses with a smaller focal range, this is not the case at all with this particular lens.
Apart from its size/weight, it doesn't fall behind in anything, for example, compared to the already very good Panasonic 12-32mm.
The stabilization system is excellent, and additionally, the lens is weather-sealed for dust/rain. It also has excellent macro capabilities, much better than the 12-32mm. The magnification ratio at the minimum focusing distance is 1:3. It may not be 1:1 like a regular macro lens, but consider that a lens like the Sigma 18-250 OS for APS-C DSLRs, which is also not a true macro lens, is called macro by Sigma with the same magnification ratio. This means that the lens will cover you in many photographic scenarios.
Finally, if you attach this lens to an Olympus camera, although they share a common mount with Panasonic, you will miss out on the excellent stabilization it has. Of course, you will rely on the IBIS that Olympus cameras have, but theoretically, as the focal distance increases, the lens stabilization surpasses the body stabilization.
This is the best general-purpose lens from any ILC system that I have ever used, and my experience so far includes the Panasonic 12-32mm, Olympus 14-42mm EZ, various 18-55mm lenses for Canon and Nikon, the 18-105, 18-140, and 18-200 for Nikon, the Sigma 18-250mm OS for Nikon, Tamron 18-200 VC for Canon, and the Sony 16-50 for E mount. It is possible that the Panasonic Leica lens with the same focal range, based on what I have read, is marginally better (not always perceptible difference for most people), but it costs three times more.

A masterpiece lens for the money. It has much better autofocus than the 12-35 f2.8 and almost the same sharpness. Since I have both lenses, the only difference is the f2.8. The only downside is the build quality externally...