The X70 starts up quickly in around two seconds, but its overall performance is surprisingly slow. The main culprit is the autofocus system, which is nice and accurate and even works well in low light, but it really takes its time over it. As a result the shot-to-shot time in single shot mode is a leisurely four seconds, and can be even slower in low light or at telephoto zoom settings. I've already mentioned the extremely fast continuous shooting mode, but needless to say that there's no focusing between shots.
Overall image quality is good, but with certain limitations. The 24x zoom lens has a focal length range equivalent to 26-624mm, and at the wide angle end it does produce quite significant distortion, however its edge to edge sharpness is very good. The telephoto end is actually surprisingly useable hand-held, thanks to a very effective sensor-shift image stabilisation system, but it does have its limits. Shutter speeds slower than about 1/100th of a second showed some movement blur, but that's not bad for such a huge magnification.
Colour rendition in default mode is very natural, and the exposure system rarely blows out a highlight, but the dynamic range of the tiny and overcrowded 1/2.3-inch sensor is quite limited, and shadow detail is restricted.
The X70's major flaw is, unfortunately, image noise. Even at 100 ISO there are some signs of colour mottling, and by 400 ISO noise is a real problem right across the image. The 3200 and 6400 ISO settings are pixel-binned to 5MP, and so are only of any use for very small pictures.
Another serious concern is battery life. The X70 is powered by a surprisingly small 925mAh battery. Even the official specification only rates it at 170 shots on a full charge, but I found that it was down to just one bar after less than 100 shots. I don't know about you, but if I'm out and about with a camera like the X70 I tend to shoot a lot of pictures, and I can quite easily shoot 100 or more in a day. 170 shots isn't even enough to fill a 1GB memory card. If you buy an X70 to take on holiday, remember to take the charger.
The Pentax X70 is a good quality camera from one of the big names in the business, and is capable of producing good pictures over a huge zoom range thanks to an excellent image stabilisation system. It handles well, and is smaller and lighter than most of its competitors, however it has a serious problem with noise even at moderate ISO settings, and the limited battery duration is also a negative point.