5
By using Google tools on your site, you give them the tools to monitor the real traffic on your site and so give you a more 'accurate' page rank, which may be lower.
I have doubts against Statcounter. It is here and there linked to SPAM or other questionable operations.
Using third party tools, doesn't come with benefits alone. You get sometimes more than wanted and give also a lot of things away. Free webservices are doing it for a reason!