If I need to track resources, their assignments and get updates on their task status, which version (integration method) makes more sense?
Answer: You can do this with Project Pro, Project Publisher, or Project Server, however there are some differences in level of detail. Starting with the most basic Project Pro sync, you can get assignments (SharePoint Assigned To field) but not assignment work, only task work. So if you have two resources assigned to a task the task in SharePoint will show both names in the Assigned To field, but the work will be the total work for the task. Working in the other direction, any updates to the task by either resource (% complete, actual work, actual finish) will update the overall task, not the assignment,
Project Publisher allows you to use Assignmnet based publishing, which allows updates at the assignment level for each resource, rather than the task level.