When I upgraded from VS6 to VS2005, I saw a 10% boost in the speed of my chess engine program with the default compile settings.
Wondering if the same is true in general, and what improvements, if any, have been made to the final output of the MS C++ compiler since then.
Regarding moving to VC++ 2010+ from versions of VC++ prior to 2010:
If you make heavy use of the STL containers and algorithms, upgrading to VC++ 2010+ may provide substantially more than just a 10% improvement, as VC++ 2010+ implement C++11's move semantics.
I recall a specific post on the Boost mailing list that claimed their application's performance increased by 900% when moving from VC++ 2008 to VC++ 2010 as a result of this:
[boost] [GGL] [geometry] Inexplicable speed benefit when using Visual C++ 2010