I've setup MySites in SharePoint 2013 and created some test sites. Everything seems to be working well except on searching people. Using search center finds the person and the link's backslash is escaped.
http://mysiteshost/Person.aspx?accountname=DOMAIN%255CUsername
This link fails to load with a "User Not Found" error. However, changing to:
http://mysiteshost/Person.aspx?accountname=DOMAIN\Username
works perfectly.
Any ideas?