I have recently upgrade sql 2012 from sp2 to sp3 and if i select @@version I do not see the SP3 version.
select @@ version
Microsoft SQL Server 2012 - 11.0.2100.60 (X64)
Feb 10 2012 19:39:15
Copyright (c) Microsoft Corporation
Enterprise Edition (64-bit) on Windows NT 6.1 <X64> (Build 7601: Service Pack 1) (Hypervisor)
Control panel shows the right version and there were no errors with the upgrade either.