SQL Server Server 2012 SP 1 upgrade vs slipstream

Hi,

I need to plan a SQL Server 2012 + SP 1 installation on a new machine.

I've read somewhere that for PowerPivot for SharePoint (2013) it is better to use the slipstream file and not the upgrade file to install after SQL Server 2012 RTM. Certainly using slipstream for a new SQL installation is more comfortable than upgrade, but I've read an explicit difference between them.

In these links I haven't found any references:

http://www.microsoft.com/en-us/download/details.aspx?id=35575

http://msdn.microsoft.com/en-us/library/jj870987.aspx

http://msdn.microsoft.com/en-US/library/jj200106(v=sql.15).aspx

Any helps to me, please? Thanks