When I joined FH, I used Adoption Centers to join a roleplay. It was before I realized that I can find a good roleplay in Fluorite Plains.
Now I don't really mind Adoption Centers, but I personally don't use them. In my opinion, Adoption Centers are generally for people that are looking for a one-day roleplay, not for a long-termed one. When someone adopts your character, you probably won't see your parents again. Or conversely. If you'll adopt a pup/cub, you probably won't see him/her/it again.
If someone wants to play as a pup/cub in a long-termed roleplay, it's better to look for one in Fluorite Plains.