Yes. In the early weeks of G+ it was really weird. I had mainly people from flickr in my circles, they were very easy to find because they actively pointed at each other. Posts like "if you're into this kind of photography you should add these people" - this was before you could share circles. They also posted how-tos on using picasa images in posts and such. They really jumped on it.

One of the reasons I often heard was that facebook reduced quality too much (bad compression) and this resulted in bad press for FB among photographers. Apparently, many were on the lookout for something like fb with an integration of something like picasa.

I'm less on flickr now because of the "please post this in our group" spam. They really need to get a grip on that.