Feedback on Link and Disjunctive Demands

In the spirit of gathering feedback from the community, here are two more feature areas we're interested in knowing how you use:

• Have you ever encountered the need to use a LinkDemand for a permission that did not inherit from CodeAccessPermission.  (For instance a custom, non-CAS permission, or one of the Principal permissions)?
• In the beta 1 release of Whidbey, we introduced a new feature called disjunctive security, which basically allows you to have multiple declarative demands on a single method that were logically or'ed together.  The major reason for introducing this feature to solve the common scenario where a method needed to be protected with a LinkDemand that would prevent anyone who wasn't signed with one of a specific set of public keys from calling into it.  Whidbey also introduced friend assemblies, which can help you achieve the same goal.  Are there other scenarios that you are using or are planning to use disjunctive security to solve, which cannot be achieved through the use of friend assemblies or other features?