database backing up, why the descrapencies?

[tinjon]

i backup using: ssh, phpmyadmin, vbulletins admincp, and my hosts cpanel.

now 4 methods give output of different sizes. following order of size.

vbulletins admincp > ssh > phpmyadmin (depends) > hosts cpanel

now i never had to restore any. but my question is, which of these method is most efficient? which contains the most data from the forum and is the best method?
how about positive and negative sides of each method?

[eva2000]

always use mysqldump via ssh telnet as other methods can time out leaving incomplete backups etc