This review is in danger of dragging on forever, so I'd best get to the important bits. £340 buys some top-quality components, and as a result the G10's overall performance is outstanding. It starts up in just over one second, and shuts down again even more quickly. The shot-to-shot time in single-shot mode varies ranges from 1.7 seconds in JPEG mode to 2.3 seconds in Raw + JPEG mode. In continuous shooting it can manage approximately 1.5 frames a second in JPEG mode, although this drops to approximately 1.3 seconds per frame in AF continuous or Raw + JPEG continuous mode, or 1.5 seconds per frame in Raw + JPEG AF continuous mode. All in all it's pretty light on its feet for a big camera.
The autofocus system is also very fast, and works reasonably well in low light, although it does slow down a bit when it has to use the AF assist lamp. It also tends to hunt around a bit at the long end of the zoom range, and starts to have real problems when shooting at longer focal lengths in low light conditions. As usual the AiAF system has a mind of its own and frequently focuses on the background rather than the main subject, but switching to center-spot AF produces much more reliable results.
In terms of image quality, I have to admit that I am slightly disappointed, but only because I had such high expectations. The level of detail that the G10 captures is simply amazing, possibly the best of any compact camera I've ever tested. However there are some problems; the lens produces noticeable chromatic aberration at the wide-angle end, with red/green fringes visible toward the edges of the frame. At longer focal lengths this is replaced with slight corner blurring and distortion.
Image noise is also not as well handled as it might be, especially when compared to previous Canon G-series models. Noise is clearly visible in shots at 200 ISO, and is causing loss of detail and problems with colour reproduction at 400 ISO. As usual with Canon cameras the texture of the noise is very grain-like, but still the results are a bit disappointing. Likewise dynamic range, which isn't much better than most other high-res compacts in the 14-megapixel range. While it does produce more shadow detail than the Nikon S710, it does so at the expense of burned-out highlights. Even the i-Contrast mode, Canon's name for a shadow brightness booster, doesn't do much to help in very high contrast situations.
Shooting in Raw mode does offer some help, and manually correcting Raw mode images can recover some shadow detail, but of course it can't help with the clipped highlights. I have to say that overall the G10's image quality, while far from terrible, suffers in comparison to its main rival the lovely Panasonic LX3, and even more so in comparison with an entry-level DSLR, proving perhaps once and for all that squeezing more megapixels onto a small compact camera sensor is not the way to produce a better camera.
The Canon PowerShot G10 is still going to be the benchmark by which all other high-spec compacts are measured, but it's no longer the top dog. It is beaten on picture quality and portability by the smaller, lighter and slightly cheaper Panasonic LX3, and is beaten badly on value for money by most entry-level DSLRs. It's still an impressive camera and can produce excellent results, especially in Raw mode, but the price means its appeal is a little too specialised for some.