a free open source program beats a $40 closed source program anyday of the week in my book.
Precisely.
What's more, if you compare the features side-by-side, DBaN certainly is superior to the free version of KillDisk, and even against the pay-for version, it does not lack the USEFUL features in relation to KillDisk.
Why pay $40 for a program which supports a few more security standards (which, to be honest, do YOU know the difference between them?) One of the best options - DoD 5220.22 M is present in both options; so $40 for this feature or $0 - You decide.