Just a short note to heap praise on
- Out of the box, B&M is configured to exclude the data from the caches, watchdog, and other huge but non-critical tables. This makes for much smaller snapshots, that download and restore much faster. And it is adjustable if you find you need some of the excluded tables, or want to exclude more.
- You can schedule B&M to automatically take snapshots of your database at set intervals, compress them, and then cull them when the get old. Try doing that with phpMyAdmin.
The Drupal documentation is chock full of warnings to backup your database before proceed. With the Backup and Migrate module on the scene, I am sure more people are actually following this excellent advice.