This is the best broad image search engine I have used. It gives you the most results, it tells you what size/resolution you can get for an image and it has the most relevant comparisons and related images in my experience. It also is the most likely to guess correctly what the source of an image is, without you needing to sift through links. It also isn't going to look at a picture of Nico Yazawa and return a generic search result like "girl," like Google will 90% of the time.
I wouldn't say it's leaps and bounds over Google in every category, but it has a pretty hard edge over it and I have had the most success with it over the years. The one flaw, for me at least as an American English speaker is that the engine returns most results in Russian. This isn't a huge problem but I can see it being a barrier for some people.