Migrating from Activiti to Flowable

We have an active BPM running in activiti.
The plan is to move to flowable latest stable version and proceed with it.

Following are my questions

  1. Is there a procedure and check list that i must fulfill to ensure that i have migrated all the active activiti processes to flowable ?
  2. A list of features/other aspects that interests/justifies to migrate from activiti to flowable (performance , web modeler etc.)

This will be help to take a decision for all those in my situation.