Our team's typical workflow is pull from repo, delete craft tables, import latest db backup, work locally.
We don't want everyone working on the dev server db for early development, because we'll be breaking the site too much for everyone else.
Which brings me to my question, should I be deleting tables before importing? If I don't delete the tables Craft has to do some cleanup magic on the backend (I don't know what it does). I do know that Craft creates tables for matrix types. Would not deleting tables potentially leave orphaned db tables? Obviously there could other side effects as well.