I like it, but it's a little buggy sometimes (caret ends up at weird places that it wouldn't otherwise -- like the beginning of a line instead of at the next logical insertion point) -- also it only seems to work if "use spaces instead of tabs" is set as your preference in the editor and I don't think there's a way to configure it... that's a shame when you have to deal with other people's projects/code and don't want to change your settings.
I have 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, and 4.5.2 all installed and I get this error message when trying to install Tab Sanity:
6/22/2015 4:43:03 PM - Beginning to install extension to Microsoft Visual Studio Premium 2013...
6/22/2015 4:43:03 PM - Install Error : Microsoft.VisualStudio.ExtensionManager.MissingTargetFrameworkException: The extension 'TabSanity' requires a version of the .NET Framework that is not installed.
at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.CheckForValidDotNetFramework(IExtension extension)
at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.CheckForInstallBlockers(InstallableExtensionImpl extension, IInstalledExtensionList modifiedInstalledExtensionsList, Boolean isNestedExtension, Boolean& olderVersionInstalled)
at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.InstallInternal(InstallableExtensionImpl extension, Boolean perMachine, Boolean isNestedExtension, IDictionary`2 extensionsInstalledSoFar, List`1 extensionsUninstalledSoFar, IInstalledExtensionList modifiedInstalledExtensionsList, AsyncOperation asyncOp, UInt64 totalBytesToWrite, UInt64& totalBytesWritten)
at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.BeginInstall(IInstallableExtension installableExtension, Boolean perMachine, AsyncOperation asyncOp)
at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.InstallWorker(IInstallableExtension extension, Boolean perMachine, AsyncOperation asyncOp)