There is no benefit from running sfc /scannow more than twice. I don't run it more than once.
DISM++, Microsoft DISM (Deployment Image Servicing and Management) & Simplix Update Pack are not the same though they have similar functions.
DISM++ is a utility for advanced users to clean, slim, backup, update or recover your Windows operating system. Deployment Image Servicing and Management (DISM.exe) is a command-line tool that can be used to service a Windows image or to prepare a Windows Preinstallation Environment (Windows PE) image.
DISM (Deployment Image Servicing and Management) (DISM) is a command-line tool that is used to mount and service Windows images before deployment. You can use DISM image management commands to mount and get information about Windows image (.wim) files or virtual hard disks (VHD). You can also use DISM to capture, split, and otherwise manage .wim files.
You can use DISM to install, uninstall, configure, and update Windows features, packages, drivers, and international settings in a .wim file or VHD using the DISM servicing commands.
DISM commands are used on offline images, but subsets of the DISM commands are also available for servicing a running operating system.
DISM is installed with Windows, and it is also distributed in the Windows Assessment and Deployment Kit (Windows ADK). DISM replaces several deployment tools, including PEimg, Intlcfg, ImageX, and Package Manager.
Simplix UpdatePack enables you to update your live Windows 7 system as well as integrate hotfixes into a Windows 7 distribution.
This update pack allows you to update Windows 7 SP1 (x86 x64) and Server 2008 R2 SP1 live operating systems, as well as to integrate the updates in the distribution (Install.wim). It can be installed in any language. Includes all critical, recommended, and security updates and updates for all versions of Internet Explorer.