I'd like to see saved searches contribute items to the full feed with the same slider volume control as for circles. But as far as I can tell they don't.
Saved searches within G+ are back and have been for some time. This post occurred half way through an incomplete update when they disappeared for a few days.
Apparently this thread won't die. It dates from a short week or so when Google's saved searches disappeared. The only thing that mildly annoys me now is that the link to save searches only appears on "Home" and not while in other places in G+
https://www.google.com/history
log in and you will find all your saved searches