For less than £450 you can't find a tiny camera with the image quality and flexibility of Canon's parade of S-series Powershot cameras. With the S120, the tradition marches on.
Canon's top point-and-shoot cameras aren't the industry leaders they were in the heydey of cameras like the S90 and the S95. While S-series cameras have gotten incrementally better over they years, they've been outstripped recently by compact competitors with larger image sensors and better image quality. Which says nothing the rapidly evolving mirrorless camera systems that are getting cheaper and cheaper. Yup, Canon S-series shooters have lost some of their luster, but luckily, their power hasn't faded with time.
The Canon S120 is virtually identical to the excellent Canon S110 except that the camera has been upgraded to a Digic 6 image processor, which improves noise reduction at higher ISOs. The new processor also enables the camera to shoot 1920 x 1080 video at up to 60 frames per second, whereas before it could only record 30 fps at Full HD resolution. Canon claims that all of its Digic 6 cameras cut both autofocus time and shutter lag in half.
Otherwise, we're looking at the S110: 12.1-megapixel 1/1.7-inch image sensor very similar Wi-Fi connectivity options, a responsive touchscreen LCD screen, and a 5x zoom lens, which opens all the way up to f/2.0.
Bottom line: The S120 will be a great camera for the same reason as its predecessors all the way back to the S90 in 2009. You can't argue with great image quality in very compact camera, which manages to cram a lot of manual operability into not a lot of space.
The S120 hits in October for £450. Short of splurging £650+ for the one of the two very best compact zoom cameras from Sony, this is the probably the way to go. (Also note that every time Canon bumps the specs on one of these little guys, the predecessors start getting blown out on Amazon. Shop around before you buy.
The G16 is slightly smaller and lighter than the G15, but it's still not going to fit in your pocket. Not even close. As before, the bigger body compared to the S120 gives the camera space for a viewfinder and a faster f/1.8 lens. The G16 also plays catch-up with new Wi-Fi connectivity that was missing before.
We've already been over the rest above: Digic 6 processor, a 12.1-megapixel CMOS sensor, 60 fps video at Full HD resolution.
And as with every G-series camera, the G16 a much less compelling product than its S-series counterpart because it's not as small. The £530 price tag doesn't help either.