Improving/Resolving keyboard input lag with Visual Studio 2013
Solution 1:
I also experienced serious keyboard lag when typing with VS2013. For me, things got much better by uninstalling one particular plugin:
Tools --> Extensions and Updates --> Uninstall Application Insights
I don't remember installing this plugin, but it's called Application Insights Tools for Visual Studio. The referenced page mentions that this extension is a preview, for what it's worth.
Solution 2:
I had same experience with VS 2013 ultimate.
It got much better when i disabled CodeLens feature.
(you can find it in Options -> Text Editor -> All Languages -> CodeLens -> uncheck Enable CodeLens)