Despite the many similarities between the Z200 and the Z100, for some reason the camera's overall performance is very different, and not in a good way. It takes nearly three seconds to start up, and nearly as long to shut down again, which is very slow by current standards. In single-shot mode at maximum image quality the shot-to-shot time was approximately 2.5 seconds, which is again extremely slow. I thought that maybe the large size of the image files in this mode (over 7MB for some shots) was the cause, but the performance is the same in lower quality modes.
In continuous shooting the Z200 fares slightly better, averaging 1.7 seconds per shot, but this is still far from quick. This is strange, because previous Casio models have been noted for their excellent performance, and indeed the autofocus system is just as good as ever, focusing quickly and accurately in a wide range of lighting conditions, including excellent low light performance with a good AF assist lamp for total darkness.
One aspect of the camera's performance is outstanding though. Like the Z100 the Z200 has a massive 1300mAh Li-ion battery for which Casio claims 400 shots on a single charge. Using the camera over several days including taking a couple of hundred shots this claim seems to hold up, which will be useful for anyone considering the Z200 as a holiday camera.
In terms of image quality the Z200 unfortunately also has good points and bad. It is, not surprisingly, very similar to the Z100, producing extremely detailed shots with virtually no compression artefacts, good colour rendition and better-than-average dynamic range, although like the Z100 it also tends to burn out highlights. Image noise is also handled very well, with minimal noise at 50-200 ISO, and reasonably subtle noise reduction at higher settings producing a granular effect rather than the usual detail-smearing usually seen in consumer compacts.
The only major image quality problem is one I've seen a number of times from Casio compacts; despite producing very little wide-angle barrel distortion, and having good centre sharpness, the lens produces severe blurring in the corners of the frame at wide angle, particularly in the top right corner. I have no idea why this should be such a common problem on Exilim compacts, but I have seen it on a number of previous models. Perhaps Casio should look at changing its lens supplier, because this recurring problem seriously compromises what would otherwise be one of the best ultra-compact cameras on the market.
The Casio Exilim EX-Z200 has many good points. It is well made, easy to use, has a number of very useful and technically advanced features including an effective mechanical image stabilisation system, and it is very competitively priced. Unfortunately it is let down by sluggish performance, and the recurring problem of corner blurring seriously jeopardises what would otherwise be excellent image quality.