>I'm not aware of any reason why that would be the case. SQL 2012 has some big performance boosts with the new columnstore index, and they rewrote the buffer pool associated with that. But out of the box, to the best of my knowledge I wouldn't expect SQL 2012 to be faster just by removing the emulation.

It is in fact a strange one. I have a few people confirming this this morning.

What we did was to do the following steps:

Change Compatibility level to SQL Server 2012 (110)
Adjust Main.ini, which includes the connection string, to add this at the end of the connection string: ;Type System Version=SQL Server 2012
The above operation forces ASP.NET to use SQL Server 2012 library files, by default ASP.NET will insist to use SQL Server 2008 library files even if the 2012 version are installed
Uninstall Microsoft System CLR Types for SQL Server
Uninstall SQL Server 2008 R2 Management Objects

So, all that remains is:

Microsoft System CLR Types for Microsoft SQL Server System 2012 x86
Microsoft SQL Server 2012 Shared Management Objects x86
Microsoft System CLR Types for Microsoft SQL Server System 2012 x64
Microsoft SQL Server 2012 Shared Management Objects x64

Presently, the last two are not used because our application is still compiled in 32 bits.