Here's my opinion on Google local business listings in niche's that I observe in services and outlets:
The samples are too small
They clutter the page
Either build another Yellow Pages , separately to the SERP's page , or leave it alone
And sure, No 1 trophy position produces 30 -50 % less traffic than before - so Google might be into a " look for more profit" drive with all the page clutter.
What's your view ?