While they are similar in size, they are different beasts.

The M9 has a bit of a drop point, the Dogfather does not. The Dogfather has less weight in the tang to accept the res-c handle. All this (including the extra length) is going to mean that the extra forward weight will make it a better chopper.

However, chopping is only one aspect. What do you want your big knife to do? Nobody can answer that but you.

Personally, I have never had a big knife that could even close to what a decent axe can do. Chopping is not what I personally like about big knives.

The drop point style of the M9 will be better for piercing. The point closer to the centerline also changes the feel of the knife as well, and some of its intended uses.

Not saying that one is better than the other. Just pointing out the differences.

You just need to decide what it is you want a big knife to do for you.

B