In our performance tests, the Exilim EX-Z70 scored well, mostly. It took 1.6 seconds to start up and capture its first JPEG, and took 1.84 seconds between subsequent JPEGs with the flash turned off, but slowed considerably to 3.36 seconds between JPEGs with the flash turned on. Shutter lag measured a fairly speedy 0.55 second in our high contrast test, which mimics bright shooting conditions, and 1.2 seconds in our low contrast test, which mimics dim shooting conditions. In continuous shooting mode, we were able to capture a none-too-impressive average of 0.73 frames per second when shooting 7.2-megapixel JPEGs. In the camera's Quick Capture mode, you can speed things up a bit, but since the camera doesn't focus between shots, you'll likely end up with a lot of useless shots.
While the EX-Z75 does a decent job dealing with color--we saw adequately accurate color reproduction in our test images--it disappoints in most other areas of image quality. Its automatic white balance did a decent job of neutralizing color when shooting under our lab's very yellow tungsten hot lights, but we were still left with a very slight yellow cast in our images. The tungsten setting did a much better job, as did the manual white balance setting. Unfortunately, we saw image artifacts in all our shots, and though they weren't hideously fuzzy by any stretch, they weren't the sharpest images we've seen, either.
At the camera's lowest sensitivity setting of ISO 50, there isn't much noise, but noise does start to creep in at ISO 100, though you'll only really notice it if viewing on a monitor; it likely won't show up in prints. Noise is significantly worse at ISO 200, decreasing sharpness further, though shadow detail is largely unaffected and prints are still definitely usable. Again noise increases noticeably at ISO 400 and continues to hurt sharpness, but images are still usable, though you'll likely not want to print images shot at ISO 400 full size. If you want to ratchet ISO up past 400, you're out of luck. Compared to a lot of the cameras on the market, that puts the EX-Z75 at a serious disadvantage, though given its price this becomes another sacrifice to hit a low price point.
Given its price, and the fact that most cameras in this price range yield similar image quality and often slower performance, the Casio Exilim EX-Z75 is actually a decent deal and sports a more attractive design than much of its competition. However, if you're looking for a camera that captures pleasing pictures, you should really shell out a little extra cash and go for something such as Canon's PowerShot SD1000 or Sony's Cyber-shot DSC-T10. If you'd like another option in this price range, you can take a look at the Olympus FE-240, though it's much slower and doesn't offer as sleek a design or the plethora of scene modes you'll get with the Z75.