And now I wonder if I should change back to the one I used to have.
I have different avatars for different sites, depending on what the convention is at any particular site. Some seem to favor pictures of yourself, so I do that, and one rotates between new themes every month, and I update accordingly. I usually use a panda avatar until I figure out what the "norm" is, and if there isn't one, I leave it.
Not too long ago I was in a thread that was over half cat avatars, and I switched mine and have just left it.
If I'm not familiar with an avatar, I usually can visually identify a poster with their signature, if not their name. It doesn't bother me when people constantly switch; I'm only bothered when multiple people have nearly identical avatars.