MacBook Pro: OS X reinstall is taking "forever", (over 12 hours) to finish
This is not common.  I have never had this problem and I upgrade to every new version.

I always create a bootable USB installer.  Here are the instructions from Apple: http://support.apple.com/kb/HT5856.  This will let you check your disk and reformat.  I always reformat so that I know everything is the way it is supposed to be, but it is a bit more time consuming.