The Canon G16 is almost a carbon copy of the G15. The only noticable differences include the addition of a newer processor and Wi-Fi. In real world use I didn't notice a difference in the processor speed, but I was able to download images to my smartphone once I initially set up the Wi-Fi connection. Setting up the Wi-Fi connection was not as intuitive as I had hoped. Yet, once the connection was in place the images transferred easily.
I am pleased to report that I love the G16 as much as I loved the G15. The camera takes high quality images. The great devide between point and shoot image quality and entry level DSLR image quality is almost intangible with modern cameras (without pixel peeping). In fact, when you factor in that the G16 has a maximum aperture of f1.8 at wide angle and an amazing f2.8 at 5x zoom, it's hard to overlook the G16. A similar DSLR set-up would cost you 2-3 times this price and it can't be thrown into your jacket packet or purse.
Here's the bottom line: the G16 is great, but if you don't need (or want) Wi-Fi save $100 and purchase the G15. The G16 currently sells for about $550.