A couple of neighbors adopt older dogs. We never discussed that specifically, yet it seems to be a smaller commitment lifetime-wise (few years instead of 10-15 for a young dog), and you'd have to train and deal with a puppy energy (which is a great thing if you have the time and energy to engage in it) if you adopt younger dogs, while the older ones seem to be well set in their good behavior ways. Long walks, established routine, no drama. Also of course fostering is a gateway drug into getting a dog as well as good way to learn what dog would be a match for you.