I don't think exploits in established programs, like browsers, will be prevented by the lack of admin privileges. I might be wrong on that.
Yes, you are wrong. The issue isn't UAC, it's the fact that the user is running with administrator rights:
http://www.zdnet.com/admin-rights-key-to-mitigating-vulnerabilities-study-shows-7000026428/
http://arstechnica.com/information-...ows-flaws-mitigated-by-removing-admin-rights/
Disabling UAC as an administrator just removes the last opportunity for the user to be made aware of an attempted install.
I have always kept UAC at default. 