I am getting ready to do a server migration to new hardware. I just want to get some input/advice on whether I should go with Server 2012 or 2008 R2. The customers environment is a mixed environment of Windows XP, Windows 7 and Windows Vista. The server is being used as a fileserver, DHCP, DNS, SQL Server for the most part. They have shares configured for accessing files, quickbooks data and a shared database. I have never used Server 2012 and am just a little leery due to the fact this customer is a medium size business and cannot afford issues after install due to compatibility and things of that sort with server 2012. So any opinions/advice would be greatly appreciated?