I currently have around 11 Task Sequences (Image Workflows) within MDT.
One of the features within MDT that I've been relying heavily upon to reduce overheard when making changes to workflows is using package references.
This allows me to create package bundles of items common to multiple images in a single location opposed to having to update each workflow.
This is especially useful when changes such as introducing new applications is done.

We primarily utilize a thin imaging workflow where most systems receive the same Wim containing Windows and MS Office + updates then package installation and configuration is done during the post-imaging phase.

Here is a technical example of one of my MDT Image workflows. This one is for Employee Workstations.
- MDT applies the wim file.
- Standard MDT mid level tasks are preformed.
- Administrator account credentials are set based upon the deployment share (RSA)
- Packages are installed depending upon the image workflow.
- Package group applicable to all systems within the orginization are installed.
7-Zip
Mozilla Firefox (ESR)
Google Chrome Enterprise
Adobe Air
Adobe Flash Player
Adobe Shockwave Player
FileZilla FTP Client
Java Runtime Environment
VLC Media Player
Enterprise Baseline configuration package (Includes settings for windows as well as settings that are applied to the default user profile)

• Package group applicable to all Employee Workstations within the organization are installed.
  VOIP Desktop Client
  Accessibility Software
  Screen Capture Software
  Employee Workstation configuration package (Includes settings for windows as well as settings that are applied to the default user profile)

• Package group applicable to Employee Workstations at the specific site are installed.
  Items such as additional bookmarks, applications and configurations which vary site to site.

  • Applications selected within the deployment wizard are installed.
  • Generic local account is created

There are several workflows which are essentially a copy of the one above but have department specific software or configurations that are applied on top of them.
What I want to avoid is having several images that are essentially duplicates of one-another with minor over the top differences and having to make modifications to each one when there are changes to the baseline workflows, such as adding, updating or dropping a package/script.

Task groups have cut the amount of work I need to perform down but cannot perform live changes across multiple image workflows.