Yeah, I don't remember when dropbox started prompting me for photos, but I know it was after my galaxy nexus started uploading them automatically for me... which I find to be quite convenient. I don't really use G+ for anything else, but I've grown quite reliant of that particular feature recently.

Though, I believe the use case GP is describing might be a bit different, depending on whether or not a dedicated camera is being used and how large the image files are...