Depends on how many files and how many changes you have.
If you have lots of changes in a few files. It's better to get the "change pack" and replace the changed files.
If you have a few changes in a lot of files, it's better to get the "patch pack" and manually replacing the lines.
I have lot of changes in few files (includes/constants.php, posting.php and modcp.php) but most changes is exactly in modcp.php and this file was changed (I thinking it because in list of changes is this: Fixed bug in moderator control panel where certain parameters could lead to an "error creating new session" sql error) but i don't know how important is patch in this file... (i never have any problems like error creating new session