Hello, finally, from the UK where I have grey squirrels in my garden and in the park behind my house.
What do they look like, and how do they compare to their US cousins? Well, I suppose I'd say they seem to be a bit smaller based on those I've seen in the US. But maybe the US ones just happened to be well fed couch potatoes, whereas the ones who visit my garden are desperate for food.
When I get a moment, I'll find and add some photos of them here.