HSA enrollment all year

As of 01-jan-2016, we are looking to allow employees to enrol and make changes to 2 plans throughout the year without a life event.

We are thinking of setting up an Unrestricted Program with the Unrestricted Plans. We have setup new plan types, attached those plan types to existing options, created new plans and a new program.

Currently the plans are set up as Must be in Program and attached to our only Program. We are thinking of end dating these as of 31-Dec-2015 and adding the new unrestricted setup as of 01-Jan-2016.

What are the pro’s and con’s of setting up the plan as Must be  in Program vs May not be in Program?