A few thoughts after a some use:
I was part of a community of people I liked, and now,
after I clicked a button, that was gone. I miss those people already. I don't recall anything on the text that clearly said "oh yeah, stuff will be gone, including your friends, and we meant to do that."
If I want to share now, I have to do so publicly with the Internet or click a "share" button way in the upper right and then build up groups. There does not seem to be an easy way to get my friends back and to get them into a reader feed. I apparently have to look at my G+ feed if a friend sends me an item. I do not seem to have any convenient way to filter out those useful posts from all the spam of G+.
I had easy access to search a list of things that I had found interesting over the years, and now, I guess I'm going to have to find another program to even look at that. I do appreciate that it was not outright destroyed, so thanks for that kindness.
Visually, I'm baffled. Apparently, grey and slightly darker grey are now visually effective colors for distinguishing things. I can, of course, adjust to this but overall it does not instill me with confidence.
I am, obviously, now looking for a way back to what I had this morning. If someone figures that out, I'll thank them. If it's something that needs support, I'll support it.